The Company accounts for stock-based compensation granted to employees and directors, including stock option awards, restricted stock and restricted stock units (“RSUs”) in accordance with FASB ASC Topic 718, “Compensation – Stock Compensation” (“ASC 718”). Accordingly, stock-based compensation cost is measured at grant date, based on the fair value of the award, and is recognized as expense over the employee’s service period. The Company recognizes compensation expense on a ratable basis over the requisite service period of the award.

The Company values options using the Black-Scholes option pricing model. Time-based RSUs are valued at the grant date fair value of the underlying common shares. Performance-based RSUs without market conditions are valued at grant date fair value of the underlying common shares. Performance-based RSUs granted with market conditions and performance-based stock options with market conditions are valued using the Monte Carlo simulation model. The Black-Scholes option pricing model requires the use of highly subjective and complex assumptions which determine the fair value of stock-based awards, including the option’s expected term and the price volatility of the underlying stock. The Monte Carlo simulation model incorporates assumptions for the holding period, risk-free interest rate, stock price volatility and dividend yield.

The terms of awards granted during the three months ended April 1, 2023 were consistent with those described in the consolidated financial statements included in our Annual Report on Form 10-K for the year ended December 31, 2022.

The following table shows stock-based compensation expense included in the condensed consolidated statements of operations for the three months ended April 1, 2023 and April 2, 2022 (in thousands):


	Three Months Ended
	April 1, 2023		April 2, 2022
Cost of revenues	$	61	$	60
Research and development		52		29
Sales and marketing		121		122
General and administrative		239		173
	$	473	$	384

Stock-based compensation expense capitalized to inventory was immaterial for the three months ended April 1, 2023 and April 2, 2022.

As of April 1, 2023, there was $1.9 million of total unrecognized compensation cost, net of expected forfeitures, related to non-vested stock-based compensation arrangements. The cost is expected to be recognized over a weighted average period of 1.57 years.

The following table summarizes stock options information during the three months ended April 1, 2023:


	Number of Shares			Weighted Average Exercise Price Per Share		Aggregate Intrinsic Value (thousands)
Outstanding as of December 31, 2022		2,232,967		$	4.27
Granted		17,400			2.28
Exercised		(17,499	)		2.16
Canceled or forfeited		(84,854	)		4.06
Outstanding as of April 1, 2023		2,148,014		$	4.28	$	1

The weighted average grant date fair value of the options granted was $1.39 and $2.85 per share for the three months ended April 1, 2023 and April 2, 2022, respectively.

The Company uses the Black-Scholes option-pricing model to estimate the fair value of stock-based awards (options) with the following weighted average assumptions:


	Three Months Ended
	April 1, 2023			April 2, 2022
Average risk free interest rate		3.83	%		2.43	%
Expected life (in years)	4.41			4.5
Dividend yield		—	%		—	%
Average volatility		76	%		76	%

Option-pricing models require the input of various subjective assumptions, including the option’s expected life and the price volatility of the underlying stock. The expected stock price volatility is based on analysis of the Company’s stock price history over a period commensurate with the expected term of the options, trading volume of the Company’s stock, look-back volatilities and Company-specific events that affected volatility in a prior period. The expected term of employee stock options represents the weighted average period the stock options are expected to remain outstanding and is based on the history of exercises and cancellations on all past option grants made by the Company, the contractual term, the vesting period and the expected remaining term of the outstanding options. The risk-free interest rate is based on the U.S. Treasury interest rates whose term is consistent with the expected life of the stock options. No dividend yield is included as the Company has not issued any dividends and does not anticipate issuing any dividends in the future.

Information regarding stock options outstanding, vested, expected to vest, and exercisable as of April 1, 2023 is summarized below:


	Number of Shares		Weighted Average Exercise Price		Weighted Average Remaining Contractual Life (Years)		Aggregate Intrinsic Value (thousands)
Options outstanding		2,148,014	$	4.28		4.96	$	1
Options vested and expected to vest		2,086,540	$	4.30		4.92	$	1
Options exercisable		976,337	$	4.87		3.76	$	1

The aggregate intrinsic value in the table above represents the pre-tax intrinsic value, based on the Company’s closing price as of April 1, 2023, that would have been received by option holders had all option holders exercised their stock options as of that date. This amount changes based on the fair market value of the Company’s common stock. The total intrinsic value of options exercised for the three months ended April 1, 2023 and April 2, 2022 was approximately $4 thousand and $19 thousand, respectively.

Information regarding RSUs activity for the three months ended April 1, 2023 is summarized below:


	Number of Shares
Outstanding as of December 31, 2022		473,029
RSUs forfeited		(30,960	)
Outstanding as of April 1, 2023		442,069