STATEMENT OF CHANGES IN CONVERTIBLE PREFERRED STOCK AND STOCKHOLDERS' EQUITY (DEFICIT) - USD ($) $ in Thousands	Common Stock [Member]	Additional Paid-In Capital [Member]	Stock Subscribed Not Issued [Member]	Accumulated Other Comprehensive Income Loss [Member]	Accumulated Deficit [Member]	Total
Begining balance at Dec. 31, 2016	$ 10	$ 72,069	$ 59		$ (61,311)	$ 10,827
Begining balance (in shares) at Dec. 31, 2016	10,157,292		8,500
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock sold for cash, net of fees	$ 6	5,247				5,253
Issuance of common stock sold for cash, net of fees (in shares)	5,860,000
Issuance of common stock for services		552	$ (59)			493
Issuance of common stock for services (in shares)	168,206		(8,500)
Issuance of common stock for services, related parties		659				659
Issuance of common stock for services, related parties (in shares)	204,683
Issuance of common stock options for services		2,576				$ 2,576
Issuance of common stock upon cashles exercise of stock options (in shares)						18,000
Cashless exercise of options
Cashless exercise of options (in shares)	14,014
Option forfeitures and expirations (in shares)
Net loss					(12,286)	(12,286)
Ending balance at Dec. 31, 2017	$ 16	$ 81,103			(73,597)	7,522
Ending balance (in shares) at Dec. 31, 2017	16,404,195
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock sold for cash, net of fees	$ 5	5,127				5,132
Issuance of common stock sold for cash, net of fees (in shares)	5,357,052
Issuance of common stock for services		36				36
Issuance of common stock for services (in shares)	221,193
Stock-based compensation		1,691				1,691
Issuance of common stock upon exercise of warrants	$ 2	2,212				$ 2,214
Issuance of common stock upon exercise of warrants (in shares)	1,475,659
Issuance of common stock upon cashles exercise of stock options
Issuance of common stock upon cashles exercise of stock options (in shares)	13,900					49,000
Issuance of warrants		1,693				$ 1,693
Warrant antidilution price protection adjustment		333			(333)
Option forfeitures and expirations		(67)				(67)
Option forfeitures and expirations (in shares)
Net loss					(11,908)	(11,908)
Ending balance at Dec. 31, 2018	$ 24	$ 92,128			$ (85,838)	$ 6,314
Ending balance (in shares) at Dec. 31, 2018	23,471,999