Under the terms of the May 2019, June 2019, July 2019, August 2019, October 2019, November 2019 and December 2019 Convertible Notes, the Company identified derivative instruments arising from embedded conversion features.

 

The following summarizes the Black-Scholes assumptions used to estimate the fair value of the derivative liability at the dates of issuance and the revaluation dates:

 

		Year ended December 31,
		2019				2018
Volatility		114%-148		%		102%-119		%
Risk-free interest rate		1.5%-2.5		%		1.7%-2.7		%
Expected life (years)		0.9 - 1.2				0.0 - 1.3
Dividend yield			--				--

 

Changes in the derivative liability were as follows:  

 

		Level 1				Level 2				Level 3
Convertible debt and other derivative liabilities at December 31, 2017			--				--			$	7,504
Issuance of convertible debt and other derivatives			--				--				346,821
Extinguishment of convertible debt											(120,603	)
Change in fair value			--				--				(83,63	)
Convertible debt and other derivative liabilities at December 31, 2018			--				--				149,759
Conversions of convertible debt			--				--				(79,027	)
Issuance of convertible debt and other derivatives			--				--				1,138,804
Extinguishment of convertible debt			--				--				(165,887	)
Change in fair value			--				--				(330,728	)
Convertible debt and other derivative liabilities at December 31, 2019			--				--			$	712,921