Monitoring pressure changes in the inner ear induced by middle ear pressure therapy with an EFET01 device in guinea pigs

Background: As a low-cost, portable, handheld air pressure generation tool not requiring a ventilation tube, the EFET01 device has shown clinical effectiveness for intractable Ménière’s disease (MD) patients in Japan. However, no animal studies have investigated changes in inner ear pressure (P_I) when applying this device. Objective: To determine the P_I properties in response to middle ear pressure therapy (MEPT) induced by the EFET01 in guinea pigs. Material and Methods: In seven healthy guinea pigs, bi-phasic pressure pulses from −5 to 12 cm H₂O were delivered to the external ear canal and transmitted to the middle and inner ear cavities with an intact tympanic membrane. Hydrostatic pressure change in the inner ear perilymphatic compartment was measured by a servo-controlled micropipette system. Results: From eight successful ears, pressure changes in the middle ear slightly decreased and were instantly transferred to the inner ear. The EFET01 produces a bi-phasic positive/negative pressure pulse, which is approximately twice as large as the monophasic pressure pulse. Conclusion: Our study clarified the EFET01’s ability to transmit pressure and verified its effectiveness in MD patients as observed in clinical studies. Significance: The P_I properties in guinea pig response to MEPT with the EFET01 device were investigated.