| Summary of Changes in Shareholders' Equity | 
 A
summary of the changes in shareholders’ equity for the three and nine months ended September 30, 2019 and 2018 is as follows: 
  
    |   | 
  | 
      | 
  | 
  | 
      | 
  | 
  | 
    Additional | 
  | 
  | 
      | 
  | 
  | 
    Total | 
  | 
 
    |   | 
  | 
    Common
    Stock | 
  | 
  | 
    Preferred
    Stock | 
  | 
  | 
    Paid
    In | 
  | 
  | 
    Accumulated | 
  | 
  | 
    Shareholders’ | 
  | 
 
    |   | 
  | 
    Shares | 
  | 
  | 
    Amount | 
  | 
  | 
    Shares | 
  | 
  | 
    Amount | 
  | 
  | 
    Capital | 
  | 
  | 
    Deficit | 
  | 
  | 
    Equity | 
  | 
 
    | Balances at December
    31, 2018 | 
  | 
      | 
29,433,135 | 
  | 
  | 
    $ | 
29,433 | 
  | 
  | 
      | 
16,017,101.733 | 
  | 
  | 
    $ | 
6,100,182 | 
  | 
  | 
    $ | 
126,125,976 | 
  | 
  | 
    $ | 
(111,373,608 | 
) | 
  | 
    $ | 
20,881,983 | 
  | 
 
    | Compensation expense
    relating to option issuances | 
  | 
      | 
— | 
  | 
  | 
      | 
— | 
  | 
  | 
      | 
— | 
  | 
  | 
      | 
— | 
  | 
  | 
      | 
145,829 | 
  | 
  | 
      | 
— | 
  | 
  | 
      | 
145,829 | 
  | 
 
    | Issuance of common
    stock - shelf takedown, net of expenses | 
  | 
      | 
16,666,668 | 
  | 
  | 
      | 
16,667 | 
  | 
  | 
      | 
— | 
  | 
  | 
      | 
— | 
  | 
  | 
      | 
11,399,009 | 
  | 
  | 
      | 
— | 
  | 
  | 
      | 
11,415,676 | 
  | 
 
    | Issuance of common
    stock in exchange for services | 
  | 
      | 
12,500 | 
  | 
  | 
      | 
12 | 
  | 
  | 
      | 
— | 
  | 
  | 
      | 
— | 
  | 
  | 
      | 
5,988 | 
  | 
  | 
      | 
— | 
  | 
  | 
      | 
6,000 | 
  | 
 
    | Series C dividend | 
  | 
      | 
— | 
  | 
  | 
      | 
— | 
  | 
  | 
      | 
12.208 | 
  | 
  | 
      | 
413,214 | 
  | 
  | 
      | 
— | 
  | 
  | 
      | 
(413,214 | 
) | 
  | 
      | 
— | 
  | 
 
    | Net
    loss | 
  | 
      | 
— | 
  | 
  | 
      | 
— | 
  | 
  | 
      | 
— | 
  | 
  | 
      | 
— | 
  | 
  | 
      | 
— | 
  | 
  | 
      | 
(3,325,717 | 
) | 
  | 
      | 
(3,325,717 | 
) | 
 
    | Balances at March 31, 2019 | 
  | 
      | 
46,112,303 | 
  | 
  | 
    $ | 
46,112 | 
  | 
  | 
      | 
16,017,113.941 | 
  | 
  | 
    $ | 
6,513,396 | 
  | 
  | 
    $ | 
137,676,802 | 
  | 
  | 
    $ | 
(115,112,539 | 
) | 
  | 
    $ | 
29,123,771 | 
  | 
 
    | Compensation expense
    relating to option issuances | 
  | 
      | 
— | 
  | 
  | 
      | 
— | 
  | 
  | 
      | 
— | 
  | 
  | 
      | 
— | 
  | 
  | 
      | 
164,588 | 
  | 
  | 
      | 
— | 
  | 
  | 
      | 
164,588 | 
  | 
 
    | Issuance of common
    stock - shelf takedown, net of expenses | 
  | 
      | 
— | 
  | 
  | 
      | 
— | 
  | 
  | 
      | 
— | 
  | 
  | 
      | 
— | 
  | 
  | 
      | 
(65,000 | 
) | 
  | 
      | 
— | 
  | 
  | 
      | 
(65,000 | 
) | 
 
    | Issuance of common
    stock in exchange for services | 
  | 
      | 
12,500 | 
  | 
  | 
      | 
13 | 
  | 
  | 
      | 
— | 
  | 
  | 
      | 
— | 
  | 
  | 
      | 
5,988 | 
  | 
  | 
      | 
— | 
  | 
  | 
      | 
6,001 | 
  | 
 
    | Net
    loss | 
  | 
      | 
— | 
  | 
  | 
      | 
— | 
  | 
  | 
      | 
— | 
  | 
  | 
      | 
— | 
  | 
  | 
      | 
— | 
  | 
  | 
      | 
(4,806,460 | 
) | 
  | 
      | 
(4,806,460 | 
) | 
 
    | Balances at June 30, 2019 | 
  | 
      | 
46,124,803 | 
  | 
  | 
    $ | 
46,125 | 
  | 
  | 
      | 
16,017,113.941 | 
  | 
  | 
    $ | 
6,513,396 | 
  | 
  | 
    $ | 
137,782,378 | 
  | 
  | 
    $ | 
(119,918,999 | 
) | 
  | 
    $ | 
24,422,900 | 
  | 
 
    | Compensation expense
    relating to option issuances | 
  | 
      | 
— | 
  | 
  | 
      | 
— | 
  | 
  | 
      | 
— | 
  | 
  | 
      | 
— | 
  | 
  | 
      | 
232,175 | 
  | 
  | 
      | 
— | 
  | 
  | 
      | 
232,175 | 
  | 
 
    | Net
    loss | 
  | 
      | 
— | 
  | 
  | 
      | 
— | 
  | 
  | 
      | 
— | 
  | 
  | 
      | 
— | 
  | 
  | 
      | 
— | 
  | 
  | 
      | 
(3,836,549 | 
) | 
  | 
      | 
(3,836,549 | 
) | 
 
    | Balances at September 30, 2019 | 
  | 
      | 
46,124,803 | 
  | 
  | 
    $ | 
46,125 | 
  | 
  | 
      | 
16,017,113.941 | 
  | 
  | 
    $ | 
6,513,396 | 
  | 
  | 
    $ | 
138,014,553 | 
  | 
  | 
    $ | 
(123,755,548 | 
) | 
  | 
    $ | 
20,818,526 | 
  | 
 
 
  
    |   | 
  | 
      | 
  | 
  | 
      | 
  | 
  | 
    Additional | 
  | 
  | 
      | 
  | 
  | 
    Total | 
  | 
 
    |   | 
  | 
    Common
    Stock | 
  | 
  | 
    Preferred
    Stock | 
  | 
  | 
    Paid
    In | 
  | 
  | 
    Accumulated | 
  | 
  | 
    Shareholders’ | 
  | 
 
    |   | 
  | 
    Shares | 
  | 
  | 
    Amount | 
  | 
  | 
    Shares | 
  | 
  | 
    Amount | 
  | 
  | 
    Capital | 
  | 
  | 
    Deficit | 
  | 
  | 
    Equity | 
  | 
 
    | Balances
    at December 31, 2017 | 
  | 
      | 
4,928,335 | 
  | 
  | 
    $ | 
4,928 | 
  | 
  | 
      | 
18,600,100.000 | 
  | 
  | 
    $ | 
6,309,608 | 
  | 
  | 
    $ | 
101,402,570 | 
  | 
  | 
    $ | 
(101,400,797 | 
) | 
  | 
    $ | 
6,316,309 | 
  | 
 
    | Compensation expense
    relating to option issuances | 
  | 
      | 
— | 
  | 
  | 
      | 
— | 
  | 
  | 
      | 
— | 
  | 
  | 
      | 
— | 
  | 
  | 
      | 
118,324 | 
  | 
  | 
      | 
— | 
  | 
  | 
      | 
118,324 | 
  | 
 
    | Conversion of Series
    A preferred stock to common stock | 
  | 
      | 
258,300 | 
  | 
  | 
      | 
259 | 
  | 
  | 
      | 
(2,583,000 | 
) | 
  | 
      | 
(268,096 | 
) | 
  | 
      | 
267,837 | 
  | 
  | 
      | 
— | 
  | 
  | 
      | 
— | 
  | 
 
    | Series C dividend | 
  | 
      | 
— | 
  | 
  | 
      | 
— | 
  | 
  | 
      | 
1.733 | 
  | 
  | 
      | 
58,670 | 
  | 
  | 
      | 
— | 
  | 
  | 
      | 
(58,670 | 
) | 
  | 
      | 
— | 
  | 
 
    | Net
    loss | 
  | 
      | 
— | 
  | 
  | 
      | 
— | 
  | 
  | 
      | 
— | 
  | 
  | 
      | 
— | 
  | 
  | 
      | 
— | 
  | 
  | 
      | 
(2,119,397 | 
) | 
  | 
      | 
(2,119,397 | 
) | 
 
    | Balances at March 31, 2018 | 
  | 
      | 
5,186,635 | 
  | 
  | 
    $ | 
5,187 | 
  | 
  | 
      | 
16,017,101.7330 | 
  | 
  | 
    $ | 
6,100,182 | 
  | 
  | 
    $ | 
101,788,731 | 
  | 
  | 
    $ | 
(103,578,864 | 
) | 
  | 
    $ | 
4,315,236 | 
  | 
 
    | Compensation expense
    relating to option issuances | 
  | 
      | 
— | 
  | 
  | 
      | 
— | 
  | 
  | 
      | 
— | 
  | 
  | 
      | 
— | 
  | 
  | 
      | 
81,986 | 
  | 
  | 
      | 
— | 
  | 
  | 
      | 
81,986 | 
  | 
 
    | Issuance of common
    stock - shelf takedown, net of expenses | 
  | 
      | 
900,000 | 
  | 
  | 
      | 
900 | 
  | 
  | 
      | 
— | 
  | 
  | 
      | 
— | 
  | 
  | 
      | 
1,509,427 | 
  | 
  | 
      | 
— | 
  | 
  | 
      | 
1,510,327 | 
  | 
 
    | Issuance of restricted
    common stock | 
  | 
      | 
16,000 | 
  | 
  | 
      | 
16 | 
  | 
  | 
      | 
— | 
  | 
  | 
      | 
— | 
  | 
  | 
      | 
24,304 | 
  | 
  | 
      | 
— | 
  | 
  | 
      | 
24,320 | 
  | 
 
    | Net
    loss | 
  | 
      | 
— | 
  | 
  | 
      | 
— | 
  | 
  | 
      | 
— | 
  | 
  | 
      | 
— | 
  | 
  | 
      | 
— | 
  | 
  | 
      | 
(2,281,289 | 
) | 
  | 
      | 
(2,281,289 | 
) | 
 
    | Balances at June 30, 2018 | 
  | 
      | 
6,102,635 | 
  | 
  | 
    $ | 
6,103 | 
  | 
  | 
      | 
16,017,101.733 | 
  | 
  | 
    $ | 
6,100,182 | 
  | 
  | 
    $ | 
103,404,448 | 
  | 
  | 
    $ | 
(105,860,153 | 
) | 
  | 
    $ | 
3,650,580 | 
  | 
 
    | Compensation expense
    relating to option issuances | 
  | 
      | 
— | 
  | 
  | 
      | 
— | 
  | 
  | 
      | 
— | 
  | 
  | 
      | 
— | 
  | 
  | 
      | 
648,302 | 
  | 
  | 
      | 
— | 
  | 
  | 
      | 
648,302 | 
  | 
 
    | Issuance of common
    stock, Series D preferred stock, and warrants, net of expenses | 
  | 
      | 
4,436,000 | 
  | 
  | 
      | 
4,436 | 
  | 
  | 
      | 
9,364,000 | 
  | 
  | 
      | 
4,464,107 | 
  | 
  | 
      | 
7,963,085 | 
  | 
  | 
      | 
— | 
  | 
  | 
      | 
12,431,628 | 
  | 
 
    | Conversion of Series
    D preferred stock to common stock | 
  | 
      | 
7,868,000 | 
  | 
  | 
      | 
7,868 | 
  | 
  | 
      | 
(7,868,000 | 
) | 
  | 
      | 
(3,750,920 | 
) | 
  | 
      | 
3,743,052 | 
  | 
  | 
      | 
— | 
  | 
  | 
      | 
— | 
  | 
 
    | Issuance of common
    stock in exchange for services | 
  | 
      | 
12,500 | 
  | 
  | 
      | 
12 | 
  | 
  | 
      | 
— | 
  | 
  | 
      | 
— | 
  | 
  | 
      | 
5,988 | 
  | 
  | 
      | 
— | 
  | 
  | 
      | 
6,000 | 
  | 
 
    | Net
    loss | 
  | 
      | 
— | 
  | 
  | 
      | 
— | 
  | 
  | 
      | 
— | 
  | 
  | 
      | 
— | 
  | 
  | 
      | 
— | 
  | 
  | 
      | 
(2,757,835 | 
) | 
  | 
      | 
(2,757,835 | 
) | 
 
    | Balances at September 30, 2018 | 
  | 
      | 
18,419,135 | 
  | 
  | 
    $ | 
18,419 | 
  | 
  | 
      | 
17,513,101.733 | 
  | 
  | 
    $ | 
6,813,369 | 
  | 
  | 
    $ | 
115,764,875 | 
  | 
  | 
    $ | 
(108,617,988 | 
) | 
  | 
    $ | 
13,978,675 | 
  | 
 
 
 |