Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Total revenue	$ 42,031	$ 37,503
Cost of sales	23,942	19,172
Gross profit	18,089	18,331
Operating expenses:
Research and development	10,896	14,183
General and administrative	10,773	12,414
Sales and marketing	3,983	5,364
Restructuring		782
Total operating expenses	25,652	32,743
Loss from operations	(7,563)	(14,412)
Interest expense	(665)	(747)
Other (expense) income, net	(24)	490
Net loss before income taxes	(8,252)	(14,669)
Income tax expense	(260)
Net loss and comprehensive loss	$ (8,512)	$ (14,669)
Net loss per common share, basic and diluted	$ (0.45)	$ (0.85)
Weighted-average shares used to compute net loss per common share, basic and diluted	18,782,287	17,317,042
Product sales
Total revenue	$ 39,848	$ 34,595
Product sales
Total revenue	39,848	34,595
Licensing, royalty and other revenue
Total revenue	$ 2,183	$ 2,908