Consolidated Statements of Operations - USD ($) shares in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Net product revenue	$ 13,643,000	$ 10,276,000
Cost of revenue	5,342,000	3,847,000
Gross profit	8,301,000	6,429,000
Operating expenses:
Sales and marketing	1,298,000	1,604,000
Research and development	1,314,000	1,237,000
General and administrative	1,182,000	1,112,000
Operating income	4,507,000	2,476,000
Interest expense	(46,000)	(189,000)
Interest income	4,000
Income from operations before income taxes	4,465,000	2,287,000
Income tax provision
Net income	4,465,000	2,287,000
Preferred stock dividends accrued	(139,000)	(139,000)
Net income attributable to common stockholders	$ 4,326,000	$ 2,148,000
Net income per share attributable to common stockholders, basic (in dollars per share)	$ 0.32	$ 0.16
Net income per share attributable to common stockholders, diluted (in dollars per share)	$ 0.28	$ 0.14
Weighted average common shares outstanding:
Basic (in shares)	13,502	13,049
Diluted (in shares)	15,352	15,063