Continuous 24-hour Measurement of Middle Ear Pressure

Abstract

A new method was developed for continuous measurement of the middle ear pressure during a 24-h period. The equipment consisted of a piezo-electric pressure device and a digital memory. To allow continuous pressure recordings during normal every-day activities the equipment was made light and portable. The measurement accuracy of the equipment as well as the base-line and temperature stability were tested and found to meet to our requirements satisfactorily. In 4 volunteers with different middle ear conditions, a small perforation was made through the tympanic membrane. A rubber stopper containing a small polyethylene tube was fitted into the external ear canal. Tubal function tests were made to establish the equipment's ability to monitor fast pressure changes. The tests were well in accordance with other methods of direct pressure measurements. The equipment was carried by the volunteers for 24 h to monitor any slow or rapid dynamic pressure changes in the middle ear. Four continuous 24-h measurements are presented. The method was found to be suitable for valid measurements of dynamic pressure changes in the middle ear during normal every-day activities. It may become a useful instrument in the search for a better understanding of the development of chronic middle ear disease.

Quasi-static Transfer Function of the Rabbit Middle Ear‚ Measured with a Heterodyne Interferometer with High-Resolution Position Decoder

“…These quasi-static pressure variations are orders of magnitude larger than the highest sound pressures, and have been measured both indirectly and directly by many authors (e.g., Flisberg et al 1961;Hergils and Magnuson 1985;Tideholm et al 1996). Recently, we reported results of ME pressure monitoring in intact human MEs (Dirckx et al 2000) and found pressure changes up to 1 kPa over intervals of hours and minutes (e.g., when rising from recumbent to upright position).…”

Long-term middle ear pressure measurements in inner ear disorders

“…However, even in persons without a history of middle ear disease pressure fluctuations are seen [2]. Instead patients with a middle ear dysfunction show pressure alternations over a vast range [3]. Until now, long-term analyses have not been performed in patients with inner ear disorders.…”

“…Performing only one single measurement might miss pathological pressure alterations. Especially when middle ear ventilation impairment is assumed, pressure changes most likely underlie pathological dynamics, as has been reported for known middle ear disorders such as chronic suppurative otitis media [3]. Pathological dynamics of middle ear pressure might exist in Meniere's disease, resulting in normal as well as pathological pressure values.…”

“…Disorders with known ET dysfunction show deteriorated middle ear pressure control. Fluctuation during continuous pressure measurements in patients with chronic suppurative otitis media reached pressure values of -250 daPa [3]. In children, whose tubal function is not fully developed due to anatomic and functional reasons, middle ear pressure analysis showed daily changes over several months [4].…”

Flexibility within the middle ears of vertebrates

“…109 Positive pressures inside the middle-ear cavity give rise to a greater umbo displacement than negative pressures, 110 which may relate to the amount of flexion possible at the inter-ossicular joints in each direction. 111 Given that mammalian middle-ear pressure fluctuates slowly throughout the day, 112 the flexibility of the articulations might also contribute to accommodation of the middle-ear apparatus, allowing efficient transmission at all times.…”