Stockholders' Equity (Tables)

12 Months Ended

Dec. 31, 2021

Assumptions Used to Calculate Fair Value of Warrants

Significant inputs utilized in the valuation of the Letter Agreement Warrants were:

	December 31, 2021		December 31, 2020
	Range	Weighted Average	Range	Weighted Average
Expected volatility	82.68% - 142.86%	128.13%	120.53% - 142.07%	128.16%
Risk-free interest rate	0.95% - 1.26%	1.15%	0.26% - 0.50%	0.39%

Warrant Liability [Member]

Assumptions Used to Calculate Fair Value of Warrants

Fair value of the Letter Agreement Warrants was calculated as of their issuance date using the methods described in Note 19 using the following assumptions:

	December 5, 2017		July 30, 2018		December 11, 2018		September 26, 2019		December 23, 2019
Expected volatility	90.00%		95.29%		104.46%		110.35%		110.41%
Expected life of option, in years		7.0		7.0		7.0		7.0		7.0
Risk-free interest rate	2.80%		2.94%		2.77%		1.65%		1.84%
Expected dividend yield	0.00%		0.00%		0.00%		0.00%		0.00%