6. STOCK BASED COMPENSATION (Details - Compensation Expense) - USD ($) $ in Thousands |
3 Months Ended | |
|---|---|---|
Mar. 31, 2018 |
Mar. 31, 2017 |
|
| Allocated stock-based compensation | $ 546 | $ 1,210 |
| Research and Development [Member] | ||
| Allocated stock-based compensation | 112 | 88 |
| General and Administrative [Member] | ||
| Allocated stock-based compensation | 400 | 852 |
| Selling and Marketing [Member] | ||
| Allocated stock-based compensation | $ 34 | $ 370 |