| Fair Value of Financial Instruments | 
 Note
3 – Fair Value of Financial Instruments 
  
The
estimated fair values of financial instruments outstanding were (in thousands): 
Schedule of Estimated Fair Value of Financial Instrument  
  
    |   | 
  | 
    September
    30, 2022 (Unaudited) | 
  | 
 
  
    |   | 
  | 
      | 
  | 
  | 
    Unrealized | 
  | 
  | 
    Unrealized | 
  | 
  | 
    Fair | 
  | 
 
  
    |   | 
  | 
    Cost | 
  | 
  | 
    Gains | 
  | 
  | 
    Losses | 
  | 
  | 
    Value | 
  | 
 
  
    | Short-term
    investments | 
  | 
    $ | 
18,372 | 
  | 
  | 
    $ | 
— | 
  | 
  | 
    $ | 
(53 | 
) | 
  | 
    $ | 
18,319 | 
  | 
 
  
    | Total | 
  | 
    $ | 
18,372 | 
  | 
  | 
    $ | 
— | 
  | 
  | 
    $ | 
(53 | 
) | 
  | 
    $ | 
18,319 | 
  | 
 
   
  
  
    |   | 
  | 
    December
    31, 2021 | 
  | 
 
  
    |   | 
  | 
      | 
  | 
  | 
    Unrealized | 
  | 
  | 
    Unrealized | 
  | 
  | 
    Fair | 
  | 
 
  
    |   | 
  | 
    Cost | 
  | 
  | 
    Gains | 
  | 
  | 
    Losses | 
  | 
  | 
    Value | 
  | 
 
  
    | Short-term
    investments | 
  | 
    $ | 
23,040 | 
  | 
  | 
    $ | 
— | 
  | 
  | 
    $ | 
(29 | 
) | 
  | 
    $ | 
23,011 | 
  | 
 
  
    | Total | 
  | 
    $ | 
23,040 | 
  | 
  | 
    $ | 
— | 
  | 
  | 
    $ | 
(29 | 
) | 
  | 
    $ | 
23,011 | 
  | 
 
   
  
  
The
following table represents the Company’s fair value hierarchy for its financial assets (cash equivalents and investments) (in thousands): 
Schedule of Fair Value Hierarchy Financial Assets  
  
    |   | 
  | 
    Fair
    Value | 
  | 
  | 
    Level
    1 | 
  | 
  | 
    Level
    2 | 
  | 
  | 
    Level
    3 | 
  | 
 
    |   | 
  | 
    September
    30, 2022 (Unaudited) | 
  | 
 
  
    |   | 
  | 
    Fair
    Value | 
  | 
  | 
    Level
    1 | 
  | 
  | 
    Level
    2 | 
  | 
  | 
    Level
    3 | 
  | 
 
  
    | Money
    market funds | 
  | 
    $ | 
2,319 | 
  | 
  | 
    $ | 
2,319 | 
  | 
  | 
    $ | 
— | 
  | 
  | 
    $ | 
— | 
  | 
 
  
    | Corporate
    notes and commercial paper | 
  | 
      | 
18,319 | 
  | 
  | 
      | 
18,319 | 
  | 
  | 
      | 
— | 
  | 
  | 
      | 
— | 
  | 
 
  
    | Total
    financial assets | 
  | 
    $ | 
20,638 | 
  | 
  | 
    $ | 
20,638
 | 
  | 
  | 
    $ | 
—
 | 
  | 
  | 
    $ | 
— | 
  | 
 
   
  
  
    |   | 
  | 
    Fair
    Value | 
  | 
  | 
    Level
    1 | 
  | 
  | 
    Level
    2 | 
  | 
  | 
    Level
    3 | 
  | 
 
    |   | 
  | 
    December
    31, 2021 | 
  | 
 
  
    |   | 
  | 
    Fair
    Value | 
  | 
  | 
    Level
    1 | 
  | 
  | 
    Level
    2 | 
  | 
  | 
    Level
    3 | 
  | 
 
  
    | Money
    market funds | 
  | 
    $ | 
5,484 | 
  | 
  | 
    $ | 
5,484 | 
  | 
  | 
    $ | 
— | 
  | 
  | 
    $ | 
— | 
  | 
 
  
    | Corporate
    notes and commercial paper | 
  | 
      | 
23,011 | 
  | 
  | 
      | 
23,011 | 
  | 
  | 
      | 
— | 
  | 
  | 
      | 
— | 
  | 
 
  
    | Total
    financial assets | 
  | 
    $ | 
28,495 | 
  | 
  | 
    $ | 
28,495 | 
  | 
  | 
    $ | 
— | 
  | 
  | 
    $ | 
— | 
  | 
 
   
  
As
of September 30, 2022, the fair value of the derivative liability was $57,000. The details of derivative liability transactions for the
nine months ended September 30, 2022 and 2021, are as follows: 
Schedule of Derivative Liability Transactions  
  
    |   | 
  | 
    September
    30, 2022 | 
  | 
  | 
    September
    30, 2021 | 
  | 
  | 
    September
    30, 2022 | 
  | 
  | 
    September
    30, 2021 | 
  | 
 
    |   | 
  | 
    Three
    Months Ending | 
  | 
  | 
    Nine
    Months Ending | 
  | 
 
  
    |   | 
  | 
    September
    30, 2022 | 
  | 
  | 
    September
    30, 2021 | 
  | 
  | 
    September
    30, 2022 | 
  | 
  | 
    September
    30, 2021 | 
  | 
 
  
    |   | 
  | 
    (Unaudited) | 
  | 
  | 
    (Unaudited) | 
  | 
  | 
    (Unaudited) | 
  | 
  | 
    (Unaudited) | 
  | 
 
  
    | Beginning
    balance | 
  | 
    $ | 
115,000 | 
  | 
  | 
    $ | 
842,000 | 
  | 
  | 
    $ | 
138,000 | 
  | 
  | 
    $ | 
383,000 | 
  | 
 
  
    | Issuance of warrants | 
  | 
      | 
— | 
  | 
  | 
      | 
— | 
  | 
  | 
      | 
— | 
  | 
  | 
      | 
— | 
  | 
 
  
    | Change
    in fair value | 
  | 
    $ | 
(58,000 | 
) | 
  | 
    $ | 
(502,000 | 
) | 
  | 
    $ | 
(81,000 | 
) | 
  | 
    $ | 
(43,000 | 
) | 
 
  
    | Extinguishment | 
  | 
      | 
— | 
  | 
  | 
      | 
— | 
  | 
  | 
      | 
— | 
  | 
  | 
      | 
— | 
  | 
 
  
    | Ending balance | 
  | 
    $ | 
57,000 | 
  | 
  | 
    $ | 
340,000 | 
  | 
  | 
    $ | 
57,000 | 
  | 
  | 
    $ | 
340,000 | 
  | 
 
   
  
 |