Stock Based Compensation (Tables)

6 Months Ended

Jun. 30, 2021

Share-based Payment Arrangement [Abstract]

Schedule of Valuation Assumptions

The fair value of each stock option granted was estimated using the following weighted average assumptions:

	Six Months Ended June 30, 2021
Risk free interest rate	0.47%
Expected maturity	3 years
Expected volatility	1.36
Expected dividend yields	—
Weighted average grant date market value per share	$3.25

Summary of Options Granted, Exercised, Expired and Forfeited

A summary of stock options activity during the six months ended June 30, 2021 and the year ended December 31, 2020 is presented below:

	Outstanding			Exercisable
	Number of Options	Weighted Average Exercise Price		Number of Options	Weighted Average Exercise Price
Options outstanding, December 31, 2019	215,345	$	12.27	215,345	$	12.27
Expired	(107,845)	4.92		—	—
Options outstanding, December 31, 2020	107,500	$	19.64	107,500	$	19.64
Granted	300,000	3.25		—	—
Options outstanding, June 30, 2021	407,500	$	7.57	107,500	$	19.64

Shares Outstanding and Exercisable, By Exercise Price Range

Additional information as of June 30, 2021 is as follows:

	Outstanding				Exercisable
Range of price	Number of Options	Weighted Average Remaining Contractual Life (In Years)	Weighted Average Exercise Price		Number of Options	Weighted Average Exercise Price
$0.00 – $10.00	302,500	9.93	$	3.30	2,500	$	9.00
$10.01 – $20.00	97,500	1.56	19.32		97,500	19.32
$20.01 – $30.00	2,500	0.94	21.80		2,500	21.80
$30.01 – $40.00	5,000	0.70	30.20		5,000	30.20
	407,500	7.76	$	7.57	107,500	$	19.64

Schedule of Compensation Expense

Stock-based compensation expense relating to Restricted Series D Preferred Stock is allocated as follows (in thousands):

	Three Months Ended June 30,				Six Months Ended June 30,
	2021		2020		2021		2020
Research and development	$	—	$	14	$	17	$	28
Sales, general and administrative	$	—	$	15	$	16	$	27
	$	—	$	29	$	33	$	55