Experimental model standardizing polyvinyl alcohol hydrogel to simulate endoscopic ultrasound and endoscopic ultrasound-elastography

Table 1 Relationship between Young's Modulus and different densities of polyvinyl alcohol phantoms

Molecular weight	Concentration	ρ (g/cm3)1	M. Y (KPa)1
MW1 = 85000-124000	C1 = 7%	0.84 ± 0.11	380 ± 0.63
	C2 = 9%	0.92 ± 0.07	518 ± 0.50
	C3 = 12%	0.96 ± 0.13	780 ± 0.28
	C4 =15%	1.43 ± 0.63	910 ± 0.23
	C5 = 20%	1.46 ± 0.18	1050 ± 0.20
MW2 = 146000-186000	C6 = 7%	0.91 ± 0.08	395 ± 0.23
	C7 = 9%	0.97 ± 0.11	525 ± 0.20
	C8 = 12%	1.22 ± 0.24	798 ± 0.18
	C9 = 15%	1.46 ± 0.22	922 ± 0.13
	C10 = 20%	2.08 ± 0.50	1120 ± 0.10

¹The data for ρ and M.Y (Young's modulus) are the average of four measurements of each phantom.

Table 2 Strain ratios (B/A) and regions of interest: A and B

Strain ratios (B/A)
A	B	C	D	E
0.1	93.3	23	0.04	0.12
A 0.81	0.1	0.2	0.41	0.13
B 0.01	0.9	0.42	0.02	0.02
F	G	H	I	J
30.18	69.67	34.5	254.3	7.0
A 0.05	0.02	0.03	0.01	0.04
B 1.57	1.64	1.05	2.33	0.3