Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 15,485	$ 14,599
Accounts receivable, net	10,315	7,607
Inventory	5,358	5,721
Prepaid expenses and other current assets	208	270
Total current assets	31,366	28,197
Property and equipment, net	1,657	1,946
Right-of-use assets	1,970	2,313
Other assets	73	73
Total assets	35,066	32,529
Current liabilities:
Accounts payable	1,944	2,224
Accrued liabilities	2,148	2,232
Deferred revenue	3,000
Current portion of long-term debt	4,277	4,242
Operating lease liabilities	1,367	1,508
Other liabilities	37	31
Total current liabilities	12,773	10,237
Long-term debt, net of current portion	3,199	3,748
Operating lease liabilities, net of current portion	662	903
Long-term income tax liability	229	229
Total liabilities	16,863	15,117
Commitments and contingencies
Stockholders' equity:
Preferred stock, $0.0001 par value per share; 5,000,000 shares authorized; no shares issued and outstanding as of March 31, 2021 and December 31, 2020
Common stock, $0.0001 par value per share; 100,000,000 shares authorized; 19,222,342 and 19,031,556 shares issued and outstanding as of March 31, 2021 and December 31, 2020	2	2
Additional paid-in capital	175,835	174,584
Accumulated deficit	(157,634)	(157,174)
Total stockholders' equity	18,203	17,412
Total liabilities and stockholders' equity	$ 35,066	$ 32,529