Preferred Stock (Tables)

12 Months Ended

Dec. 31, 2018

Equity [Abstract]

Allocation of Net Proceeds from Redeemable Preferred Stock Financing

The net proceeds received during the year ended December 31, 2017 from the redeemable preferred stock financing were allocated as follows:

Common stock warrant liability (see Note 12)	$	3,498,632
Embedded derivative		19,857
Beneficial conversion feature		1,506,196
Initial carrying value of redeemable preferred stock		7,993,885
Net proceeds from redeemable preferred stock issuance	$	13,018,570

Summary of Periodic Changes Fair Value of Embedded Redemption Derivative Financial Instrument

The periodic changes in the fair value of the embedded redemption derivative financial instrument for the years ended December 31, 2018 and 2017 are as follows:

Balance, January 1, 2017	$	—
Issuance		19,857
Changes in fair value		7,379
Balance, January 1, 2018		27,236
Changes in fair value		(27,236	)
Balance, December 31, 2018	$	—

Assumptions Used to Estimate Fair Value of Embedded Redemption Derivative Financial Instrument

The fair value used to determine the initial carrying value of the embedded redemption derivative financial instrument was measured using Level 3 inputs and was estimated using the Monte Carlo simulation valuation model. The assumptions used to estimate the fair value of the embedded redemption derivative financial instrument at December 31, 2017 and as of the redeemable preferred stock issuance date were as follows:

	December 31, 2017
Expected volatility		59.60	%
Incremental borrowing rate		12.00	%
Risk-free interest rate		1.59	%