CONDENSED CONSOLIDATED BALANCE SHEET - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 39,487	$ 61,014
Investments	52,525	47,437
Trade accounts receivable	3,143	3,222
Inventory	8,527	8,059
Prepaid expenses	1,771	955
Other current assets	1,291	1,165
Total current assets	106,744	121,852
Property and equipment, net	8,639	7,905
Right of use assets	3,742	3,917
Other non-current assets	868	750
Total assets	119,993	134,424
Current liabilities:
Accounts payable	3,401	2,351
Accrued liabilities	2,428	3,828
Accrued interest	191	1,262
Deferred revenue	186	271
Current operating lease liability	453	450
Total current liabilities	6,659	8,162
Non-current operating lease liability	3,466	3,579
Other non-current liabilities	93	19
Convertible notes	132,717	130,043
Total liabilities	142,935	141,803
Commitments and contingencies
Stockholders’ deficit:
Preferred shares	0	0
Common stock	55	55
Contributed capital	457,987	452,344
Treasury stock	(45,067)	(45,067)
Accumulated deficit	(436,067)	(414,653)
Accumulated other comprehensive income (loss)	150	(58)
Total stockholders’ deficit	(22,942)	(7,379)
Total liabilities and stockholders’ deficit	$ 119,993	$ 134,424
Preferred Stock, par value (usd per share)	$ 0.001	$ 0.001
Preferred Stock, shares authorized (shares)	5,000,000	5,000,000
Common Stock, par value (usd per share)	$ 0.001	$ 0.001