CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 35,725	$ 35,781
Investments	21,299	32,488
Trade accounts receivable	2,269	1,550
Inventory	9,732	9,216
Prepaid expenses	978	1,172
Other current assets	1,513	1,780
Total current assets	71,516	81,987
Property and equipment, net	5,143	6,135
Right of use assets	2,679	3,183
Other non-current assets	1,823	2,120
Total assets	81,161	93,425
Current liabilities:
Accounts payable	2,330	1,290
Accrued liabilities	3,572	2,991
Accrued interest	143	1,262
Deferred revenue	469	376
Current portion of long-term debt	352	553
Current operating lease liability	645	497
Total current liabilities	7,511	6,969
Non-current operating lease liability	2,569	3,063
Other non-current liabilities	678	335
Long-term debt	72	4,659
Convertible notes	110,078	141,211
Total liabilities	120,908	156,237
Commitments and contingencies
Stockholders’ deficit:
Preferred shares, $0.001 par value	3	0
Common stock, $0.001 par value	65	58
Contributed capital	553,134	475,072
Treasury stock	(45,067)	(45,067)
Accumulated deficit	(547,865)	(492,966)
Accumulated other comprehensive (loss) income	(17)	91
Total stockholders’ deficit	(39,747)	(62,812)
Total liabilities and stockholders’ deficit	$ 81,161	$ 93,425