Consolidated Balance Sheets (Parentheticals) - USD ($)	Dec. 31, 2016	Dec. 31, 2015
Allowance for doubtful accounts	$ 10,000	$ 5,000
Furniture, fixtures & equipment, accumulated depreciation	659,144	566,477
Patents, accumulated amortization	$ 717,086	$ 646,388
Preferred stock, par value (in dollars per share)	$ 0.001	$ 0.001
Preferred stock, shares authorized (in shares)	5,000,000	5,000,000
Preferred stock, shares issued (in shares)	7,000	7,000
Preferred stock, shares outstanding (in shares)	7,000	7,000
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized (in shares)	50,000,000	50,000,000
Common stock, shares issued (in shares)	30,457,224	21,720,497
Common stock, shares to be issued (in shares)	1,270,481	963,451
Common stock, shares outstanding (in shares)	30,423,891	21,687,164
Treasury stock, at cost (in shares)	33,333	33,333