Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Net revenues
Total net revenues	$ 22	$ 259
Cost of revenues
Total cost of revenues	1,560	2,172
Gross loss	(1,538)	(1,913)
Operating expenses
Selling, general and administrative	15,475	24,533
Research and development	12,253	8,955
Total operating expenses	27,728	33,488
Operating loss	(29,266)	(35,401)
Other income (expense), net
Other income (expense), net	(14)	88
Gain on extinguishment of PPP promissory note (Note 9)	2,023
Total other income (expense), net	2,009	88
Loss from continuing operations before income taxes	(27,257)	(35,313)
Income taxes	4	7
Loss from continuing operations	(27,261)	(35,320)
Discontinued operations (Note 3)
Income (loss) from discontinued operations (including gain on sale of $3,500 in 2021) before income taxes	2,191	(725)
Income (loss) from discontinued operations	2,191	(725)
Net loss	$ (25,070)	$ (36,045)
Net income (loss) per share, basic and diluted
Continuing operations	$ (5.39)	$ (20.79)
Discontinued operations	0.43	(0.43)
Total net loss per share, basic and diluted	$ (4.96)	$ (21.22)
Weighted average common shares used in computing net income (loss) per share, basic and diluted	5,055	1,699
Product Sales [Member]
Net revenues
Total net revenues	$ 22	$ 254
Cost of revenues
Total cost of revenues	832	1,369
Service and Other [Member]
Net revenues
Total net revenues		5
Cost of revenues
Total cost of revenues	$ 728	$ 803