Equity Incentive Plans and Warrants (Tables)

9 Months Ended

Sep. 30, 2023

Equity Incentive Plans and Warrants [Abstract]

Stock Option Plan Activity

Activity under the Company’s stock option plans for the nine months ended September 30, 2023 was as follows:

	Number of options			Weighted average exercise price
Outstanding at December 31, 2022		931,550		$	3.97
Granted		5,000			1.18
Forfeited		(50,055	)		1.87
Outstanding at March 31, 2023		886,495		$	4.07
Granted		153,200			0.75
Forfeited		(20,024	)		3.94
Outstanding at June 30, 2023		1,019,671		$	3.57
Granted		1,064,800			0.49
Forfeited		(5,200	)		1.25
Outstanding at September 30, 2023		2,079,271		$	2.00
Vested and exercisable at September 30, 2023		1,217,298		$	2.62

Estimated Using Assumptions

Options granted under our 2021 Stock Option Plan for the nine months ended September 30, 2023 to employees and nonemployees were 1,150,000 and 73,000, respectively and the weighted average exercise prices were $0.52 and $0.64, respectively. The weighted-average fair values of the options granted to employees and nonemployees were $0.42 and $0.51, respectively and were estimated using the following Black-Scholes assumptions:

	Employee			Nonemployee
Expected term (in years)		5.60			5.49
Risk‑free interest rate		4.06	%		3.96	%
Dividend yield		—	%		—	%
Expected volatility		105.14	%		106.58	%

Share-based Compensation Expense

The following table shows the share-based compensation expense related to vested stock option grants to employees and nonemployees by financial statement line item on the accompanying statement of comprehensive loss:

	Three Months Ended September 30,				Nine Months Ended September 30,
	2023		2022		2023			2022
Research and development	$	79,561		10,820		131,812			73,395
Sales and marketing		623		1,515		(1,319	)		3,857
General and administrative		424,175		39,427		496,036			81,036
Total share-based compensation expense	$	504,359		51,762		626,529			158,288

Warrants Valuation Assumptions

The common stock was valued at $1,133,480, based on the Company’s stock price. The pre-funded warrants and common warrants were valued at $1,615,701 and $1,854,099, respectively, using the following Black-Scholes assumptions:

	Pre-funded warrants			Common warrants
Expected term (in years)		4			4
Risk‑free interest rate		3.83	%		3.83	%
Dividend yield		—	%		—	%
Expected volatility		100.25	%		100.25	%
Exercise price	$	0.0001		$	1.095
Stock price	$	0.86		$	0.86
Black-Scholes value	$	0.86		$	0.58