Statements of Operations - USD ($)
shares in Thousands, $ in Thousands
 12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Income Statement [Abstract]    
Revenue $ 533 $ 246
Cost of revenue 253 148
Gross margin 280 98
Operating Expenses:    
Research and development 7,748 7,318
General and administrative 5,203 4,956
Selling and marketing 954 957
Total operating expenses 13,905 13,231
Loss from operations (13,625) (13,133)
Other income/(expense):    
Interest income 325 236
Total other income/(expense), net 325 236
Net loss $ (13,300) $ (12,897)
Net loss per common share, basic and diluted $ (0.84) $ (1.02)
Weighted average number of common shares outstanding, basic and diluted 15,852 12,655