Condensed Consolidated Balance Sheets (Current Period Unaudited) - USD ($)	Sep. 30, 2022	Dec. 31, 2021
Current assets:
Cash and cash equivalents	$ 5,907,000	$ 19,162,000
Accounts receivable, net of allowance for doubtful accounts of $15 and $66 as of September 30, 2022 and December 31, 2021, respectively	860,000	549,000
Inventory	1,615,000	1,472,000
Prepaid expenses and other current assets	1,222,000	1,055,000
Total current assets	9,604,000	22,238,000
Property and equipment, net	1,009,000	1,554,000
Investment in unconsolidated limited liability company	0	577,000
Other assets	1,541,000	1,544,000
Total assets	12,154,000	25,913,000
Current liabilities:
Accounts payable	1,108,000	1,480,000
Accrued liabilities	4,101,000	3,053,000
Note payable, current portion	5,628,000	0
Total current liabilities	10,837,000	4,533,000
Note payable, noncurrent portion	0	5,124,000
Other noncurrent liabilities	133,000	1,190,000
Total liabilities	10,970,000	10,847,000
Commitments and contingences (Note 9)
Stockholders’ equity:
Common stock, $0.0001 par value; 75,000,000 shares authorized as of September 30, 2022 and December 31, 2021; 10,698,857 and 10,619,846 shares issued and outstanding as of September 30, 2022 and December 31, 2021, respectively	1,000	1,000
Additional paid-in capital	259,697,000	256,918,000
Accumulated deficit	(258,514,000)	(241,853,000)
Total stockholders’ equity	1,184,000	15,066,000
Total liabilities and stockholders’ equity	12,154,000	25,913,000
Series B Preferred Stock [Member]
Stockholders’ equity:
Convertible preferred stock	0	0
Series C Preferred Stock [Member]
Stockholders’ equity:
Convertible preferred stock	$ 0	$ 0