Measurement of Young’s Modulus of Human Tympanic Membrane at High Strain Rates

Abstract

The mechanical behavior of human tympanic membrane (TM) has been investigated extensively under quasistatic loading conditions in the past. The results, however, are sparse for the mechanical properties (e.g., Young's modulus) of the TM at high strain rates, which are critical input for modeling the mechanical response under blast wave. The property data at high strain rates can also potentially be converted into complex modulus in frequency domain to model acoustic transmission in the human ear. In this study, we developed a new miniature split Hopkinson tension bar to investigate the mechanical behavior of human TM at high strain rates so that a force of up to half of a newton can be measured accurately under dynamic loading conditions. Young's modulus of a normal human TM is reported as 45.2-58.9 MPa in the radial direction, and 34.1-56.8 MPa in the circumferential direction at strain rates 300-2000 s(-1). The results indicate that Young's modulus has a strong dependence on strain rate at these high strain rates.

Mechanical damage of tympanic membrane in relation to impulse pressure waveform – A study in chinchillas

“…Luo et al (2009) measured the TM failure stress using a miniature split Hopkinson tension bar, and their results showed that the ultimate tensile stress of the TM increased with increasing strain rate, and the orientation of TM sample had a strong influence on the ultimate tensile stress. The mean ultimate stress of TM in the circumferential direction was 7.7 MPa with a strain rate of 772/s, and 13.7 MPa with a strain rate 1353/s.…”

Dynamic Properties of Human Tympanic Membrane Based on Frequency-Temperature Superposition

“…The human TM shows typical viscoelastic properties in published papers. 5, 18, 28 To describe the viscoelastic behavior of the TM, the generalized linear solid model 19 was used in this study. Based on this model, the relaxation modulus of the TM is presented as: $$E(t)=E_0+{\displaystyle \sum _{i=1}^n}{E}_i\text{ exp}(-\frac{t}{{\tau }_i})$$ where E i (i=0,1,…., n) is the relaxation modulus of the i th spring, τ i is the relaxation time of the i th dashpot.…”

“…They converted the relaxation modulus into the complex modulus in the frequency domain and reported 45.2 – 58.9 MPa in the radial direction and 34.1 – 56.8 MPa in the circumferential direction of the TM from 100 to 2400 Hz. 18 Zhang and Gan (2010) conducted the dynamic test on human TM up to 8000 Hz using a laser Doppler vibrometer to measure the vibration of the TM sample in the strip induced by acoustic driving. The complex modulus was obtained by the inverse-problem solving method using the finite element model.…”

Experimental measurement and modeling analysis on mechanical properties of incudostapedial joint

“…While the IS joint works over the auditory frequency range (20–20,000 Hz), its dynamic properties or complex modulus under high frequency is important for understanding the middle ear function. The dynamic properties of some middle ear soft tissue, such as the TM, have been reported by Luo et al (2009). However, the frequency-dependant mechanical properties of the IS joint have not been reported and need to be investigated in our future study.…”