STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY - USD ($)
$ in Thousands
Common stock [Member]
Additional paid-in capital [Member]
Receipts on account of shares [Member]
Accumulated deficit [Member]
Total
Balance at Dec. 31, 2017 $ 11 $ 85,944 $ 0 $ (80,075) $ 5,880
Balance (in shares) at Dec. 31, 2017 18,976,169        
Stock-based compensation related to warrants and stock granted to service providers [1] 102 0 0 102
Stock-based compensation related to warrants and stock granted to service providers (in shares) 42,293        
Stock-based compensation related to stock and options granted to directors and employees [1] 917 0 0 917
Stock-based compensation related to stock and options granted to directors and employees (in shares) 147,820        
Exercise of options [1] 25 0 0 25
Exercise of options (in shares) 33,332        
Exercise and reissuance of warrants [1] 7,632 4,408 0 12,040
Exercise and reissuance of warrants (in shares) 1,558,202        
Net loss $ 0 0 0 (13,948) (13,948)
Balance at Dec. 31, 2018 $ 11 94,620 4,408 (94,023) 5,016
Balance (in shares) at Dec. 31, 2018 20,757,816        
Stock-based compensation related to warrants and stock granted to service providers [1] 25 0 0 25
Stock-based compensation related to warrants and stock granted to service providers (in shares) 5,908        
Stock-based compensation related to stock and options granted to directors and employees [1] 582 0 0 582
Stock-based compensation related to stock and options granted to directors and employees (in shares) 82,104        
Exercise of options [1] 35     35
Exercise of options (in shares) 18,665        
Exercise and reissuance of warrants [1] 7,534 (4,408)   3,126
Exercise and reissuance of warrants (in shares) 1,741,299        
Net loss $ 0 0 $ 0 (15,561) (15,561)
Balance at Sep. 30, 2019 $ 11 $ 102,796   $ (109,584) $ (6,777)
Balance (in shares) at Sep. 30, 2019 20,606,492        
[1] Represents an amount less than $1.