Consolidated Balance Sheets (Current Period Unaudited) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
CURRENT ASSETS
Cash and cash equivalents	$ 35,730	$ 69,392
Accounts receivable	490	634
Inventory, net	3,883	2,458
Prepaid expenses and other current assets	1,376	992
TOTAL CURRENT ASSETS	41,479	73,476
NON-CURRENT ASSETS
Property and equipment, net	798	858
Goodwill	2,061	2,061
Other assets	202	247
TOTAL ASSETS	44,540	76,642
CURRENT LIABILITIES
Accounts payable and accrued liabilities	8,212	10,600
Accrued bonuses	729	1,163
Other current liabilities	127	116
TOTAL CURRENT LIABILITIES	9,068	11,879
NON-CURRENT LIABILITIES
Warrant liability	2,759	12,818
Accrued dividends	129	129
Other liabilities	79	136
TOTAL LIABILITIES	12,035	24,962
Commitments and contingencies
STOCKHOLDERS' EQUITY
Preferred stock; $0.001 par value; 930,000 shares authorized; none issued and outstanding at June 30, 2022 and December 2021	0	0
Common stock; $0.001 par value; 100,000,000 shares authorized; 28,172,468 and 27,539,229 shares issued and outstanding at June 30, 2022 and December 31, 2021	28	28
Additional paid-in capital	187,380	183,912
Accumulated deficit	(170,917)	(148,274)
TOTAL STOCKHOLDERS' EQUITY	16,491	35,666
TOTAL LIABILITIES, SERIES A AND SERIES B CONVERTIBLE PREFERRED STOCK AND STOCKHOLDERS' EQUITY	44,540	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