Condensed Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 18,515	$ 23,379
Accounts receivable, net	5,982	7,522
Inventory	9,659	9,097
Prepaid expenses and other current assets	595	688
Total current assets	34,751	40,686
Property and equipment, net	4,108	4,286
Right-of-use assets	3,272
Other assets	73	73
Total assets	42,204	45,045
Current liabilities:
Accounts payable	1,692	2,637
Accrued liabilities	4,424	5,001
Current portion of long-term debt	5,972	5,977
Lease liabilities	1,542
Total current liabilities	13,630	13,615
Long-term debt, net of current portion	5,075	6,509
Lease liabilities, net of current portion	2,117
Total liabilities	20,822	20,124
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, 2019 and December 31, 2018
Common stock, $0.0001 par value per share; 100,000,000 shares authorized; 17,108,063 and 17,095,456 shares issued and outstanding as of March 31, 2019 and December 31, 2018	2	2
Additional paid-in capital	159,629	158,912
Accumulated deficit	(138,249)	(133,993)
Total stockholders’ equity	21,382	24,921
Total liabilities and stockholders’ equity	$ 42,204	$ 45,045