Condensed Consolidated Statements of Comprehensive Loss (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Income Statement [Abstract]
REVENUES	$ 79	$ 115	$ 276	$ 396
OPERATING EXPENSES
Research and development	4,609	3,584	13,628	10,185
Sales, marketing and administration	2,952	3,002	8,931	8,500
TOTAL OPERATING EXPENSES	7,561	6,586	22,559	18,685
NET OPERATING LOSS	(7,482)	(6,471)	(22,283)	(18,289)
OTHER INCOME (EXPENSE)
Interest and investment income	42	177	220	323
Other expense	(7)	8	(18)	4
TOTAL OTHER INCOME, NET	35	185	202	327
LOSS BEFORE INCOME TAXES	(7,447)	(6,286)	(22,081)	(17,962)
Provision for (benefit from) income taxes	0	(11)	1	(19)
NET LOSS	(7,447)	(6,275)	(22,082)	(17,943)
Foreign currency translation adjustment, net of tax	(16)	10	(10)	(5)
COMPREHENSIVE LOSS	$ (7,463)	$ (6,265)	$ (22,092)	$ (17,948)
NET LOSS PER SHARE - BASIC AND DILUTED (in dollars per share)	$ (0.26)	$ (0.23)	$ (0.78)	$ (0.73)
Weighted average shares outstanding-basic and diluted (in shares)	29,169,495	27,006,046	28,295,248	24,645,658