Note 4 - Summary of Significant Accounting Policies (Details Textual) - USD ($) |
6 Months Ended | |
|---|---|---|
Jun. 30, 2021 |
Jun. 30, 2020 |
|
| Research and Development Expense [Member] | ||
| Patent Expense | $ 68,000 | $ 60,000 |
| X | ||||||||||
- Definition The amount of expense associated with gaining and maintaining certain patents. No definition available.
|
| X | ||||||||||
- Details
|