Measured Hyperelastic Properties of Cervical Tissue with Shear-Wave Elastography

Sensors

Graham Brooker¹  Weirong Ge²  Ritu Mogra³  Jon Hyett³ 

[1] Australian Centre for Field Robotics, Rose Street Bldg, University of Sydney, Camperdown, NSW 2006, Australia;Faculty of Medicine and Health, University of Sydney, Camperdown, NSW 2006, Australia;Royal Prince Alfred Hospital, 50 Missenden Rd., Camperdown, NSW 2050, Australia;

关键词: shear-wave elastography;    hyperelastic materials;    cervical tissue;   

DOI  :  10.3390/s22010302

来源: DOAJ

【 摘 要 】

The nonlinear mechanical behaviour of cervical tissue causes unpredictable changes in measured elastograms when pressure is applied. These uncontrolled variables prevent the reliable measurement of tissue elasticity in a clinical setting. Measuring the nonlinear properties of tissue is difficult due to the need for both shear modulus and strain to be taken simultaneously. A simulation-based method is proposed in this paper to resolve this. This study describes the nonlinear behaviour of cervical tissue using the hyperelastic material models of Demiray–Fung and Veronda–Westmann. Elastograms from 33 low-risk patients between 18 and 22 weeks gestation were obtained. The average measured properties of the hyperelastic material models are: Demiray–Fung—$A_1\alpha$ = 2.07 (1.65–2.58) kPa, $\alpha$ = 6.74 (4.07–19.55); Veronda–Westmann—$C_1{C}_2$ = 4.12 (3.24–5.04) kPa, $C_2$ = 4.86 (2.86–14.28). The Demiray–Fung and Veronda–Westmann models performed similarly in fitting to the elastograms with an average root mean square deviation of 0.41 and 0.47 ms${}^{-1}$, respectively. The use of hyperelastic material models to calibrate shear-wave speed measurements improved the consistency of measurements. This method could be applied in a large-scale clinical setting but requires updated models and higher data resolution.

【 授权许可】

Unknown