Ultrasound Otoscopes For Aiding Diagnosis Of Middle Ear Infections

Middle ear infections are one of the most common problems for a clinical visit to an otolaryngologist. The disease is more prevalent in pediatric populations but can affect any age group.

The most common presentation is Otitis Media with Effusion/OME (i.e fluid collecting in the middle ear behind an intact tympanic membrane /eardrum). This fluid may accumulate in the middle ear as a result of a cold, sore throat or upper respiratory infection.

Most of the time OME is a self-limiting condition with the collected fluid being a harmless one. Only when secondary infection happens antibiotics are needed.

Once otitis media with effusion is suspected, the otolaryngologist will use an otoscope to visualize the eardrum(s). An otoscope is a lighted instrument that allows the physician to see inside the ear. A pneumatic otoscope blows a puff of air into the ear to test the eardrum movement.

Otoscopy

After diagnosing middle ear effusion, some advice a test called tympanometry to confirm the diagnosis. This test confirms the diagnosis and helps in determining the amount and thickness of the fluid that is trapped.

This diagnosis of middle ear infections is an easy and straightforward one for a practicing otolaryngologist. Conventional otoscopes provide a visual view into the ear, but they can’t see behind the eardrum. Secondary signs of infection are usually used to make a diagnosis, but this leads to nearly half of all cases being over-diagnosed and unnecessary antibiotics are prescribed. Such over prescriptions are considered a major cause of antibiotic resistance.

Researchers at the Fraunhofer Institute for Photonic Microsystems IPMS in Germany have developed a new ultrasound transducer, dubbed CMUT (capacitive micromachined ultrasonic transducer), that can be integrated into existing otoscopes to provide a clearer view into the middle ear and let physicians better diagnose infections within.

This special transducer coupled ultrasound otoscopes emit pulses of sound waves, which are reflected back by the eardrum. These reflected echoes are captured by an integrated microprocessor which analyzes the nature of those echoes, determining the amount and consistency of any fluid that may be present behind the eardrum, within the middle ear.

The Fraunhofer team has now partnered with OtoNexus Medical Technologies, a company based in Seattle, Washington, to embed this transducer into an otoscope and to see if it works in a clinical trial.

Incorporating these two technologies, the ultrasound otoscopes still do allow doctors to visually inspect a patient’s ear, just like a regular otoscope does but with an added benefit of precisely knowing what’s happening behind the eardrum.

According to the developers, this transducer for ultrasound otoscopes is cheap to produce and can be miniaturized so that it is much smaller than existing ultrasound technologies.

These ultrasound otoscopes are already being trialed with the hope that soon physicians will be better able to diagnose common, but poorly treated, infections of the middle ear.

Previously a group of researchers from MIT, USA developed an otoscope that uses shortwave infrared light to look for fluid behind the eardrum.[/nextpage]

Meet the author

Dr Sanu P Moideen is an Indian-born oto-rhino-laryngologist (ENT) based in Cochin, Kerala, India. He is currently working as Post-Doctoral Fellow in Head and Neck Oncology at Regional Cancer Center, Trivandrum, Kerala.

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Comments & DIscussions

    • On
      Dr Sanu P Moideen said:

      @Febin: The advantage is that the physician can immediately confirm the diagnosis rather than sending the patient for impedance and then reviewing them the same day or next day with the report. The patient also will be benefited such that visit with an audiologist and an immediate review with the physician can be avoided. In busy practices and low resource communities, this can save a lot of money and working hours even if the cost of impedance is low.

  • On
    Patrick Connolly said:

    HI Dr. Sanu,
    I have a chronic ear condition that has all the symptoms of gluey fluid in my middle ear. With hearing loss,70% approx in both ears. There is clicking, like fluid shifting in my ear. Congestion like feeling and middle ear pain. Do you know how I could volunteer for a clinical trial?

    • On
      Dr Sanu P Moideen said:

      @Connolly: Please consult an otolaryngologist near you and get evaluated to know why glue ear occurs in you on the first place. Your doctor will examine your ear, may advise you to get some hearing tests like audiometry, tymps and a nasal endoscopy done. After that definitely he will help you in recovering from the condition and will also help in rehabilitation for your hearing loss.

      At present the ultrasound otoscope is a prototype and its commercial use has not yet started. It may take years for commercialize it.

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