Spectral Gradient Acoustic Reflectometry Research Articles

Emerging Technologies for the Diagnosis of Otitis Media.

To review new experimental techniques for the diagnosis of otitis media (OM). Literature search in English in the following databases: MEDLINE (via PubMed), Ovid Medline, Google Scholar, and Clinical Evidence (BMJ Publishing) between January 1, 2005, and April 30, 2018. Subsequently, articles were reviewed and included only if relevant. MeSH terms: ["diagnosis"] AND [all forms of OM] AND ["human"] AND ["ear"] and ["tympanic membrane"]. The retrieved innovative diagnostic techniques rely on and take advantage of the physical properties of the tympanomastoid cavity components: tympanic membrane (TM) thickness, its translucency and compliance; middle ear fluid characteristics; biofilm presence; increased tissue metabolic activity in OM states; and fluid presence in the mastoid cavity. These parameters are taken into account to establish OM diagnosis objectively. We review spectral gradient acoustic reflectometry, digital otoscopy, TM image analysis, multicolor reflectance imaging, anticonfocal middle ear assessment, optical coherence tomography, quantitative pneumatic otoscopy, transmastoid ultrasound, wideband measurements, TM thickness mapping, shortwave infrared imaging, and wideband acoustic transfer functions. New experimental techniques are gradually introduced to overcome the limitations of standard otoscopy. The aforementioned techniques are still under investigation and are pending widespread clinical use. The implementation of these techniques in the market is dependent on their success in clinical trials, as well as on their future cost. New techniques for the diagnosis of OM can objectively evaluate the morphology of the TM, determine the presence of middle ear fluid and evaluate its content, and thus potentially replace standard otoscopy.

DIAGNOSTIC AND THERAPEUTIC ALGORITHMFOR ACUTE OTITIS MEDIA

Acute otitis media is acutely developed inflammation of the middle ear cavities manifested by one or more characteristic symptoms (earache, fever, discharge from ear, hearing loss in children excitement, irritability, vomiting, diarrhea). The use of clinical guidelines based on the principles of evidence-based medicine allows accurately diagnosing the disease and avoiding the unnecessary use of antibiotics. Methods of instrumental diagnostics of acute otitis media include pneumatic otoscopy, tympanometry and spectral gradient acoustic reflectometry. Antibacterial and symptomatic treatment, including analgesics, antipyretics, eliminates the general and local symptoms within 48-72 h.

Can trained nurses exclude acute otitis media with tympanometry or acoustic reflectometry in symptomatic children?

Objective Since acute otitis media (AOM) is the most prevalent bacterial infection in young children, the reliable exclusion of AOM by nurses might save physicians’ time for other duties. The study aim was to determine whether nurses without otoscopic experience can reliably use tympanometry or spectral gradient acoustic reflectometry (SG-AR) to exclude AOM.Design Three nurses were trained, who performed examinations with tympanometry and SG-AR. Pneumatic otoscopy by the study physician served as the diagnostic standard.Setting Study clinic at primary health care level.Patients. 281 children 6–35 months of age.Main outcome measures Predictive values (with 95% confidence interval) for tympanometry and SG-AR, and the clinical usefulness, i.e. the proportion of visits where nurses obtained the exclusive test result from both ears of the child.Results At 459 visits, the negative predictive value of type A and C1 tympanograms (tympanometric peak pressure >–200 daPa) was 94% (91–97%). Based on type A and C1 tympanograms, the nurse could exclude AOM at 94/459 (20%) of visits. The negative predictive value of SG-AR level 1 result (>95°) was 94% (89–97%). Based on the SG-AR level 1 result, the nurse could exclude AOM at 36/459 (8%) of visits.Conclusion Type A and C1 tympanograms and SG-AR level 1 results obtained by nurses are reliable test results in excluding AOM. However, the clinical usefulness of these test results is limited by their rarity. Type A and C1 tympanograms were obtained by nurses from both ears of the child only at one-fifth of the symptomatic visits.Key PointsAcute otitis media (AOM) is the most prevalent bacterial infection in young children. Nurses’ role in excluding AOM is unknown.Type A and C1 tympanograms (tympanometric peak pressure >–200 daPa) obtained by nurses are reliable test results in excluding AOM.With type A and C1 tympanograms, nurses could exclude AOM only at one-fifth of the symptomatic visits.The clinical usefulness of the exclusion of AOM performed by nurses seems to be limited.

Parental role in the diagnostics of otitis media: can layman parents use spectral gradient acoustic reflectometry reliably?

ObjectiveSpectral gradient acoustic reflectometry (SG-AR) can be used to detect middle ear effusion (MEE). Since both families and primary health care systems carry the burden of otitis media, our aim was to determine whether layman parents could be taught to use the SG-AR reliably. MethodsWe enrolled 359 children (age 6–35 months) whose parents were willing to use SG-AR at home. The parents were asked to perform bilateral SG-AR daily on their child. In this study, we included children who had undergone successful parental home SG-AR examination performed on the same day that a physician had also performed successful SG-AR examination and pneumatic otoscopy at the study clinic. We compared the parental and study physician SG-AR examination results to the study physicians′ pneumatic otoscopy, which served as the diagnostic standard. ResultsWe analyzed 571 successful parental home SG-AR examinations performed on the same day that a study physician had performed a successful SG-AR examination and pneumatic otoscopy at the study clinic. None of the evaluated SG-AR level combinations resulted in both high sensitivity and specificity. For symptomatic visits, the negative predictive value of a parental SG-AR level 1 to detect MEE was 64%. For parental SG-AR levels 4–5, the positive predictive value to detect MEE was 88%. However, for asymptomatic visits, the negative predictive value of a parental SG-AR level 1 to detect MEE was 83%. ConclusionThis study showed that layman parents are able to use the SG-AR technically successfully. In symptomatic children, parentally obtained SG-AR level 1 examination is not adequate to exclude MEE. However, parentally obtained SG-AR levels 4–5 do indicate the presence of MEE. At the same time, in asymptomatic children, parentally obtained SG-AR level 1 examination seems to indicate a healthy middle ear. From the perspective of primary care, the implementation of parental SG-AR examinations in the diagnostic chain of otitis media would be intriguing. This study showed that the possibilities lie in the follow up of the resolution of MEE after an episode of OM in asymptomatic children. However, it seems that currently, the SG-AR technique is an obstacle for wider clinical implementation.

Improvement in otitis media with effusion in patients undergoing tracheostomy after prolonged endotracheal intubation.

Otitis media with effusion (OME) has a higher incidence in adult intensive care unit (ICU) patients. This observational study sought to examine the effect of tracheostomy on OME in critically ill patients and explore the predisposing factors. Twenty-seven ICU patients who had undergone prolonged intubation (more than 14 days) received traditional tracheostomies. Otoscopic examination, tympanometry, and spectral gradient acoustic reflectometry were performed both at the time of the tracheostomy and 7 days later. We collected data on the patients' demographics (age and gender), underlying diseases, duration of intubation prior to the tracheostomy, history of gastroesophageal reflux disease, length of antibiotic use, level of consciousness, and presence of nasogastric tubes. At the time of the tracheostomy, 25 (46%) ears from 14 (52%) patients were classified as cases of OME, 17 (31%) ears and 7 (26%) patients as normal cases, and 12 (11%) ears from 6 (11%) patients as cases of negative pressure in the tympanic cavity. Seven days after the tracheostomy, OME was resolved in 17 (68%) ears and persisted in 6 (24%) ears, whereas negative pressure developed in 2 (8%) ears. Our data showed that the incidence of OME reduced from 46% to 22% after tracheostomy was performed on the patients. The incidence of OME in adult ICU patients who were intubated for more than 14 days was found to reduce after tracheostomy. Notably, the rate of improvement in the conscious patients was significantly higher than that in the unconscious patients.

Can nurses exclude middle-ear effusion without otoscopy in young asymptomatic children in primary care?

Objective. Scandinavian guidelines recommend controlling middle-ear effusion (MEE) after acute otitis media. The study aim was to determine whether nurses without otoscopic experience can reliably exclude MEE with tympanometry or spectral gradient acoustic reflectometry (SG-AR) at asymptomatic visits. Design. Three nurses were taught to perform examinations with tympanometry and SG-AR. Pneumatic otoscopy by the study physician served as the diagnostic standard. Setting. Study clinic at primary health care level. Patients. A total of 156 children aged 6–35 months. Main outcome measures. Predictive values (with 95% confidence interval) for tympanometry and SG-AR, and the clinical usefulness, i.e. the proportion of visits where nurses obtained the exclusive test result from both ears of the child. Results. At 196 visits, the negative predictive value of type A and C1 tympanograms (tympanometric peak pressure > −200 daPa) was 95% (91–97%). Based on type A and C1 tympanograms, the nurse could exclude MEE at 81/196 (41%) of visits. The negative predictive value of SG-AR level 1 result was 86% (79–91%). Based on SG-AR level 1 results, the nurse could exclude MEE at 29/196 (15%) of visits. Conclusion. Tympanograms with tympanometric peak pressure > −200 daPa (types A and C1) obtained by nurses are reliable test results in excluding MEE. However, these test results were obtained at less than half of the asymptomatic visits and, thus, the usefulness of excluding MEE by nurses depends on the clinical setting.

Comparison of Spectral Gradient Acoustic Reflectometry and Tympanometry for Detection of Middle-ear Effusion in Children

Spectral gradient acoustic reflectometry (SGAR) and tympanometry are handy methods to aid in the diagnostics of middle-ear diseases, but no prior studies have directly assessed the correlation between SGAR and tympanometry readings in children. We compared SGAR and tympanometry in 2152 otoscopic examinations among 600 children aged 0.6-14 years, who were examined for signs and symptoms of respiratory infection in a primary care setting; 677 (31.5%) of the ear examinations were in children <3 years of age. We further determined the test characteristics of these methods for the detection of middle-ear effusion (MEE) using pneumatic otoscopy as the gold standard. All examinations were performed by trained physicians. SGAR and tympanometry indicated probable absence of MEE in 1896 (88.1%) and 1937 (90.0%) of the 2152 ears, respectively. SGAR levels 1-2 were observed in 95.7% of ears with type A/As tympanogram and in 58.1% of ears with type B tympanogram. The frequency of type B tympanogram increased with increasing SGAR levels, from 4.8% at SGAR level 1 to 67.7% at SGAR level 5. The observed agreement between the 2 methods was 86%. The test characteristics of SGAR and tympanometry for the detection of MEE diagnosed by pneumatic otoscopy were comparable. The high specificities and negative predictive values of SGAR and tympanometry make them useful aids particularly in ruling out MEE in children with respiratory infections. The low cost, easy portability and absence of need for an airtight seal support the use of SGAR also for screening purposes at home.

Applicability of spectral gradient acoustic reflectometry (EarCheck): Screening patients who need surgical treatment for chronic otitis media with effusion

ObjectivesWe aimed to conduct a prospective, observational study of the applicability of EarCheck (Innovia Medical LLC, Omaha, NE) in the surgical management of chronic otitis media with effusion (COME). Materials and methodsBetween February 2013 and July 2013, 84 patients (165 ears) who had been diagnosed with COME and underwent surgical management were recruited. Information concerning patient sex, age, body mass index, EarCheck score, pure-tone averages (PTAs), speech reception thresholds (SRTs), and characteristics of middle ear fluid (MEF) were documented and statistically analyzed. ResultsMEF was detected in 87.3% (n=144/165) of the 165 ears. Based on EarCheck scores ≥3 (as a criterion for abnormal findings), the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of EarCheck were 56.9%, 90.5%, 82%, 23.5%, and 61.2%, respectively. Significant positive correlation was found between EarCheck, both pure-tone thresholds at all frequencies and mean PTAs, and SRTs. The mean PTAs and SRTs of the patients with EarCheck scores ≥3 was 37.79dB and 33.26dB, respectively; these scores were significantly higher than the mean PTAs and SRTs (30.56dB and 25.88dB, respectively) of the patients with EarCheck scores <3 (p<0.05). ConclusionAlthough it is not preferable to conduct the EarCheck test alone when diagnosing COME because of its low accuracy, because of its additional hearing level clues, EarCheck can be used in deciding whether to perform tympanostomy tube insertion when conventional audiometry is not possible.

Acoustic Reflectometry in Discrimination of Otoscopic Diagnoses in Young Ambulatory Children

Studies concerning spectral gradient acoustic reflectometry (SG-AR) have analyzed middle ear effusion only as 1 entity. The usefulness of SG-AR to detect specific otoscopic diagnoses of otitis media in young children is unknown. Among 515 children aged 6-35 months, we compared SG-AR with pneumatic otoscopy and evaluated the proportions of 5 manufacturer-recommended SG-AR levels in relation to specific otoscopic diagnoses in 2802 and 1240 examinations at symptomatic and asymptomatic visits, respectively. At symptomatic visits, when the angle value was >95° (level 1), healthy middle ear was diagnosed in 76% of otoscopic examinations and acute otitis media in 5%. Levels 2 (70-95°) and 3 (60-69°) did not relate to any otoscopic diagnosis. Levels 4 and 5 associated with acute otitis media in 50% and 64%, and otitis media with effusion in 33% and 32% of examinations, respectively. At asymptomatic visits, levels 1, 2 and 3 were associated with healthy middle ear in 87%, 71% and 54% of examinations, respectively. With levels 4 and 5, otitis media with effusion was diagnosed in 62% and 79% of examinations, respectively. SG-AR is not useful in making specific otoscopic diagnoses. Although the extremities of 5 SG-AR levels are able to differentiate ears with and without effusion, SG-AR is not able to differentiate acute otitis media from otitis media with effusion. Therefore, SG-AR can aid in diagnostics, but careful pneumatic otoscopy is needed to determine accurate diagnoses.

Availability of Spectral Gradient Acoustic Reflectometry

Background and Objectives Spectral gradient acoustic reflectometry (SGAR) determines the probability of middle ear fluid by measuring the response of the tympanic membrane to a sound. To assess the sensitivity and specificity of SGAR for the diagnosis of otitis media with effusion (OME) in the Korean population, we compared accurate diagnostic rates of OME obtained from SGAR and tympanometry. Pneumatic otoscope was used for diagnostic standard of OME. Subjects and Method SGAR and tympanometry were performed on 488 ears from May 27th, 2008 to July 30th, 2008. Exclusion criteria were the presence of tympanic membrane perforation, and/or pressure equalization tubes, noncompliance, otorrhea, external auditory canal stenosis and signs of acute inflammation such as fever or otalgia. In all cases, pneumatic otoscopic examination was conducted and diagnostic accurate rates of OME were calculated in SGAR and tympanogram. Results Using spectral gradients of 3 or higher as breakpoints for indicating OME, in the case of pediatrics under 2 years old, with the sensitivity of 58.3%, specificity of 94.7%, positive predictive value (PPV) of 77.8% and negative predictive value (NPV) of 87.8%. In the case of the pediatrics between 2 and 12 years old, it showed the sensitivity of 67.2%, specificity of 90.3%, PPV of 74.5% and NPV of 86.8%. In the case of the pediatrics over 12 years old, they showed sensitivity of 87.3%, specificity of 88.8%, PPV of 67.6% and NPV of 96.3%. Conclusion SGAR has the higher tendency of specificity and NPV, and will be a useful screeningtest with good portability and economical efficiency.

Spectral Gradient Acoustic Reflectometry Compared With Tympanometry in Diagnosing Middle Ear Effusion in Children Aged 6 to 24 Months

To evaluate the accuracy of spectral gradient acoustic reflectometry (SGAR) in children aged 6 to 24 months, and to compare SGAR with tympanometry. Comparison of diagnostic tests. Inner-city primary care center in Pittsburgh, Pennsylvania. A total of 786 healthy children aged 6 to 24 months. Test characteristics of SGAR (sensitivity, specificity, and positive and negative predictive values) and receiver operating characteristic curves from the SGAR and tympanometric data. The SGAR results were available for 3096 otoscopic examinations in 647 children. Tympanometric results were available for 2854 otoscopic examinations in 597 children. Using the recommended SGAR pass or fail cutoff, 53% of the ears in which effusion was present would have been considered effusion free (sensitivity, 47%). Only 10% of the ears without effusion would have been considered to have effusion (specificity, 90%). The area under the receiver operating characteristic curve was 0.78 for SGAR and 0.83 for tympanometry. Spectral gradient acoustic reflectometry is slightly less discerning than tympanometry in predicting the presence or absence of middle ear effusion in children younger than 2 years.

Tympanometry or Reflectometry for Confirming Middle Ear Effusion

Accurate diagnosis of acute otitis media (AOM) or otitis media with effusion depends on the presence of middle ear effusion (MEE). Tympanometry and spectral gradient acoustic reflectometry (SGAR) are noninvasive methods for detecting MEE. To compare the accuracy of the two methods, researchers analyzed data from an AOM vaccine study in …

Spectral gradient acoustic reflectometry in the diagnosis of middle-ear fluid in children

Diagnosis of otitis media is based on detection of middle-ear fluid (MEF) and is both important and difficult to achieve. Also non-infectious MEF is important to detect, since it can compromise hearing. In this prospective, blinded study, spectral gradient acoustic reflectometry (SG-AR) was evaluated as an indicator of MEF among children. Sensitivity, specificity and positive and negative predictive values of SG-AR in detecting MEF were calculated in children undergoing ambulatory surgery for recurrent or secretory otitis media using otomicroscopic myringotomy as the reference method of confirming middle-ear status. Final study material consisted of 376 ears. Pattern recognition of SG-AR curves reached the best combination of sensitivity and specificity (69 and 97%, respectively), and the best combination of positive (PPV) and negative (NPV) predictive values (93 and 83%, respectively), in detection of MEF. With a spectral gradient value of <80 degrees , the sensitivity was 75% and specificity 71%. With <50 degrees , PPV was 78%, and with >or=100 degrees , NPV was 86%. The diagnostic power of SG-AR was comparable to that reported with pneumatic otoscopy and tympanometry. It was equally effective in detecting both MEF cases and healthy ears. Pattern recognition seems to improve its performance. We recommend the use of pattern recognition of SG-AR as a screening method for MEF among children.

Middle ear effusion in intensive care unit patients with prolonged endotracheal intubation

Objectives The purpose of this study is to explore the factors related to the occurrence of middle ear effusion (MEE) in prolonged endotracheal intubation patients in the intensive care unit (ICU). Methods Information about the age, sex, duration of endotracheal intubation, level of consciousness, and placement of nasogastric tube was retrospectively collected from medical charts of 20 prolonged endotracheal intubation (>7 days) patients in the ICU. All patients received otoscopic examination, tympanometry studies, and spectral gradient acoustic reflectometry for evidence of MEE. Results Among the 40 ears examined in this study, 20 ears had MEE (50%), 14 ears were normal (35%), and 6 ears had negative pressure in the middle ear (15%). In addition, patients with conscious disturbance and those who had been intubated for 14 days had a significantly higher incidence of MEE. Nasogastric tube was not implicated in MEE in this study. No episodes of acute otitis media or systemic infection were encountered in this study. Conclusions Prolonged endotracheal intubation (>7 days) in adult ICU patients contributed to the high incidence of MEE (50%). Moreover, conscious disturbance and endotracheal intubation for 14 days were also significant contributing factors of MEE.

Detection of middle-ear fluid in children with spectral gradient acoustic reflectometry: A screening tool for nurses?

Objective. To evaluate the validity of spectral gradient acoustic reflectometry (SG-AR) in the hands of nurses in screening children for middle-ear fluid (MEF). Design. Prospective, blinded study. Setting. A satellite study within the Finnish Otitis Media Vaccine Trial in primary care in 1995–99. Patients. Some 739 ear examinations among a cohort of 271 children under the age of 2 years during different healthcare contacts (acute sick visits, check-up visits after otitis media, and scheduled healthy control visits at 24 months of age). Main outcome measures. Specificity, sensitivity and positive and negative predictive values of SG-AR performed by nurses in detecting MEF using pneumatic otoscopy by trained physicians as a reference. Results. SG-AR was successful in 585 (79%) ears. None of the cut-off points assessed resulted in both excellent sensitivity and specificity. Nevertheless, at the sick visits, positive predictive values at 50 and 60 degrees were as high as 94% and 89%, respectively. However, negative predictive value for the cut-off point of 100 degrees was considerably lower, at 75%. At the non-acute visits, negative predictive values were excellent. Conclusion. SG-AR is a useful device for nurses in screening MEF among children. It detects ears with both very high and very low probability of MEF and is especially effective in detecting MEF during sick visits and in ruling out MEF among non-acute patients. We recommend the use of the SG-AR cut-off point of 60 degrees as a sign of MEF when screening sick children, and the cut-off point of 100 degrees as a sign of a healthy ear among non-symptomatic patients.

Home Monitoring of Middle Ear Fluid by Parents Using Spectral Gradient Acoustic Reflectometry

Home Monitoring of Middle Ear Fluid by Parents Using Spectral Gradient Acoustic Reflectometry

Spectral gradient acoustic reflectometry for the detection of middle ear effusion by pediatricians and parents.

Spectral gradient acoustic reflectometry for the detection of middle ear effusion by pediatricians and parents.