Quarterly report pursuant to Section 13 or 15(d)

BALANCE SHEETS (Unaudited) (Parenthetical)

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BALANCE SHEETS (Unaudited) (Parenthetical) - USD ($)
Mar. 31, 2020
Dec. 31, 2019
Statement of Financial Position [Abstract]    
Accounts receivable, allowance for doubtful accounts $ 32,645 $ 32,645
Patents, accumulated amortization $ 303,425 $ 288,967
Common stock, par value (in dollars per share) $ 0.01 $ 0.01
Common stock, authorized 75,000,000 75,000,000
Common stock, issued 42,423,977 42,239,788
Common stock, outstanding 39,686,746 39,502,557
Treasury stock 2,737,231 2,737,231