Stock Based Compensation	6 Months Ended
Stock Based Compensation	Jun. 30, 2023
Stock Based Compensation [Abstract]
Stock Based Compensation	Note 5 — Stock Based Compensation Our stockholders approved the Amended and Restated Equity Incentive Plan (the “A&R Plan”) at our annual shareholders’ meeting in June 2023, which added 3,500,000 shares to the plan. Our prior plan expired March 29, 2023; no further awards will be made under the prior plan, but the A&R Plan will govern awards granted under the prior plan. At June 30, 2023, there were 5,253,971 shares available for grant under the A&R Plan. Stock-based compensation expense included in general and administrative expense was $393 and $487, and in research and development expense was $289 and $325, for the three months ended June 30, 2023 and 2022, respectively. Stock-based compensation expense included in general and administrative expense was $764 and $953, and in research and development expense was $600 and $637, for the six months ended June 30, 2023 and 2022, respectively. During the three months ended June 30, 2023, we granted options for a total of 37,500 shares with a weighted average grant date fair value of $0.35 per option. During the three months ended June 30, 2022, we granted options for a total of 801,004 shares with a weighted average grant date fair value of $1.09 per option. During the six months ended June 30, 2023, we granted options for a total of 37,500 shares with a weighted average grant date fair value of $0.35 per option. We estimated the fair value of the options on the date of grant utilizing the Black-Scholes valuation model with the following assumptions: (i) 0 percent dividend yield, (ii) 81 percent volatility, (iii) 4% risk free rate and (iv) 6 years expected term. During the six months ended June 30, 2022, we granted options for a total of 801,004 shares with a weighted average grant date fair value of $1.09 per option. We estimated the fair value of the options on the date of grant utilizing the Black-Scholes valuation model with the following assumptions: (i) 0 percent dividend yield, (ii) 86 percent volatility, (iii) 3 percent risk free rate and (iv) 6 years expected term. During the three months ended June 30, 2023 and 2022, we granted 24,999 and 258,363 RSUs respectively, with weighted average fair values at the date of grant of $0.50 and $1.46, respectively. RSUs, which are subject to forfeiture if service terminates prior to the shares vesting, are expensed ratably over the vesting period. During the three months ended June 30, 2023 and 2022, we paid $5 and $29 in withholding taxes on shares issued upon conversion of RSUs, respectively. The underlying shares were cancelled. The amounts are reflected as financing costs in the accompanying statement of cash flows. No RSUs were granted during the first three months of 2023 or 2022. As of June 30, 2023, the unrecognized stock-based compensation expense related to non-vested stock options and RSUs was $3,009 and $1,074, respectively, which will be amortized over an estimated weighted average period of approximately 2.25 and 2.24 years, respectively. During the three and six months ended June 30, 2023 and 2022 no options were exercised. During the three months ended June 30, 2023 and 2022, we issued 215,255 and 191,795 shares as a result of vesting RSUs, respectively. No shares were issued during the first three months of 2023 or 2022 as a result of vesting RSUs. During the three ended June 30, 2023 and 2022, there were 213,125 and 255,000 options returned to the plan due to the 10-year expiration for unexercised options respectively. During six months ended June 30, 2023 and 2022, there were 253,125 and 255,000 options returned to the plan due to the 10-year expiration for unexercised options respectively.