Condensed Consolidated Statements of Operations (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Revenue:
Total revenue	$ 86	$ 239	$ 302	$ 438
Costs and expenses:
Cost of goods sold	191	135	297	292
Research and development	2,219	2,031	4,385	3,986
Selling, general and administrative	1,438	1,325	3,070	3,032
Total costs and expenses	3,848	3,491	7,752	7,310
Operating loss	(3,762)	(3,252)	(7,450)	(6,872)
Other income (expense):
Interest income	13	35	36	71
Other expense	(1)		(1)
Total other income	12	35	35	71
Net loss	$ (3,750)	$ (3,217)	$ (7,415)	$ (6,801)
Net loss per share, basic and diluted (in dollars per share)	$ (0.77)	$ (0.76)	$ (1.53)	$ (1.60)
Weighted-average shares used in computing net loss per share, basic and diluted (in shares)	4,847,829	4,249,698	4,847,746	4,249,192
Product [Member]
Revenue:
Total revenue	$ 62	$ 89	$ 139	$ 171
Collaboration Agreement [Member]
Revenue:
Total revenue	$ 24	$ 150	$ 163	$ 267