Consolidated Balance Sheets (Current Period Unaudited) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
CURRENT ASSETS
Cash and cash equivalents	$ 52,499	$ 69,392
Accounts receivable	698	634
Inventory, net	3,839	2,458
Prepaid expenses and other current assets	712	992
TOTAL CURRENT ASSETS	57,748	73,476
NON-CURRENT ASSETS
Property and equipment, net	828	858
Right of use assets	204	230
Goodwill	2,061	2,061
Security deposit	17	17
TOTAL ASSETS	60,858	76,642
CURRENT LIABILITIES
Accounts payable and accrued liabilities	12,716	10,600
Accrued bonuses	394	1,163
Other current liabilities	120	116
TOTAL CURRENT LIABILITIES	13,230	11,879
NON-CURRENT LIABILITIES
Warrant liability	5,410	12,818
Accrued dividends	129	129
Other liabilities	106	136
TOTAL LIABILITIES	18,875	24,962
STOCKHOLDERS' EQUITY
Preferred stock; $0.001 par value; 930,000 shares authorized; none issued and outstanding at March 31, 2022 and December 2021	0	0
Common stock; $0.001 par value; 100,000,000 shares authorized; 27,539,229 shares issued and outstanding at March 31, 2022 and December 31, 2021	28	28
Additional paid-in capital	185,000	183,912
Accumulated deficit	(159,059)	(148,274)
TOTAL STOCKHOLDERS' EQUITY	25,969	35,666
TOTAL LIABILITIES, SERIES A AND SERIES B CONVERTIBLE PREFERRED STOCK AND STOCKHOLDERS' EQUITY	60,858	76,642
Series A Convertible Preferred Stock [Member]
NON-CURRENT LIABILITIES
Preferred stock	13,708	13,708
Series B Convertible Preferred Stock [Member]
NON-CURRENT LIABILITIES
Preferred stock	2,306	2,306
Commitments and contingencies