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Equity Incentive Plans - Stock-Based Compensation (Details) - USD ($)
$ / shares in Units, $ in Thousands
3 Months Ended 6 Months Ended 9 Months Ended 12 Months Ended
Mar. 31, 2022
Jun. 30, 2022
Sep. 30, 2022
Dec. 31, 2022
Dec. 31, 2021
Dec. 31, 2020
Equity Incentive Plans            
Total stock-based compensation expense $ 764 $ 1,433 $ 1,969 $ 2,493 $ 3,338 $ 2,818
Common stock options            
Equity Incentive Plans            
Total stock-based compensation expense       $ 2,493 $ 3,338 $ 2,818
Assumptions used to compute employee stock based compensation under the Black-Scholes option pricing model            
Expected dividend yield (as a percent)       0.00% 0.00% 0.00%
Expected life (in years)       6 years 3 months 6 years 3 months 6 years 3 months
Unrecorded deferred stock-based compensation            
Unrecorded deferred stock-based compensation balance related to stock options       $ 3,300    
Weighted-average amortization period over which cost is expected to be recognized       2 years 9 months 18 days    
Weighted average grant date fair value of options granted (in dollars per share)       $ 3.29    
Common stock options | Cost of goods sold            
Equity Incentive Plans            
Total stock-based compensation expense       $ 133 $ 271 $ 14
Common stock options | Research and development            
Equity Incentive Plans            
Total stock-based compensation expense       372 490 651
Common stock options | Selling and marketing            
Equity Incentive Plans            
Total stock-based compensation expense       155 148 108
Common stock options | General and administrative            
Equity Incentive Plans            
Total stock-based compensation expense       $ 1,833 $ 2,429 $ 2,045
Common stock options | Minimum            
Assumptions used to compute employee stock based compensation under the Black-Scholes option pricing model            
Risk-free interest rate (as a percent)       1.71% 66.00% 0.40%
Expected volatility (as a percent)       107.00% 105.00% 65.00%
Common stock options | Maximum            
Assumptions used to compute employee stock based compensation under the Black-Scholes option pricing model            
Risk-free interest rate (as a percent)       4.22% 1.51% 1.68%
Expected volatility (as a percent)       118.00% 106.00% 106.00%
Unvested restricted stock units            
Unrecorded deferred stock-based compensation            
Unrecorded deferred stock-based compensation balance related to stock options       $ 68,000,000    
Weighted-average amortization period over which cost is expected to be recognized       8 months 12 days