CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Current assets:
Cash and cash equivalents	$ 27,329	$ 63,419
Short-term investments	103,402	83,560
Accounts receivable, net of allowance for doubtful accounts of $258 and $264, respectively	12,682	14,246
Inventory	14,705	11,498
Prepaid expenses and other current assets	3,143	3,143
Total current assets	161,261	175,866
Property and equipment, net	10,276	8,992
Operating lease right-of-use assets	4,917	5,248
Other non-current assets	395	400
TOTAL ASSETS	176,849	190,506
Current liabilities:
Accounts payable	4,998	3,198
Accrued liabilities and other	9,169	12,353
Operating lease liabilities, current portion	1,286	1,339
Total current liabilities	15,453	16,890
Long-term borrowings	35,024	34,973
Operating lease liabilities, net of current portion	3,889	4,166
Other long-term liabilities	45	57
TOTAL LIABILITIES	54,411	56,086
Commitments and contingencies (Note 6)
STOCKHOLDERS’ EQUITY
Preferred stock, $0.0001 par value; 5,000,000 shares authorized; no shares issued and outstanding	0	0
Common stock, $0.0001 par value; 100,000,000 shares authorized; 33,872,363 and 33,674,085 shares issued and outstanding, respectively	3	3
Additional paid-in capital	435,590	429,914
Accumulated other comprehensive income	104	352
Accumulated deficit	(313,259)	(295,849)
TOTAL STOCKHOLDERS’ EQUITY	122,438	134,420
TOTAL LIABILITIES AND STOCKHOLDERS’ EQUITY	$ 176,849	$ 190,506