Statements of Operations (Unaudited) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Revenue:
Total revenue	$ 5,345,455	$ 6,798,111	$ 11,101,696	$ 13,807,985
Sublease	246,530	251,996	493,060	493,061
Cost of revenue:
Total cost of revenue	1,084,981	1,147,492	2,036,396	2,559,545
Sublease	246,530	246,531	493,060	493,061
Gross margin	4,260,474	5,650,619	9,065,300	11,248,440
Operating expenses:
Research and development	1,976,942	2,695,162	4,086,112	5,654,381
Sales and marketing	2,541,749	3,236,516	5,457,173	6,546,342
General and administrative	1,663,456	1,178,469	3,496,181	2,646,629
Total operating expenses	6,182,147	7,110,147	13,039,466	14,847,352
Operating loss	(1,921,673)	(1,459,528)	(3,974,166)	(3,598,912)
Interest income	567	31,810	81,529	48,374
Net loss	(1,921,106)	(1,427,718)	(3,892,637)	(3,550,538)
Cumulative dividend on convertible preferred stock	(342,126)	(357,194)	(685,849)	(710,704)
Loss attributable to common stockholders	$ (2,263,232)	$ (1,784,912)	$ (4,578,486)	$ (4,261,242)
Net loss per share attributable to common stockholders:
Basic	$ (0.03)	$ (0.03)	$ (0.06)	$ (0.07)
Diluted	$ (0.03)	$ (0.03)	$ (0.06)	$ (0.07)
Weighted average number of common shares and equivalents:
Basic	71,628,762	60,052,673	70,749,401	59,936,606
Diluted	71,628,762	60,052,673	70,749,401	59,936,606
Systems [Member]
Revenue:
Total revenue	$ 12,769	$ (0)	$ 12,769	$ 58,051
Cost of revenue:
Total cost of revenue	157,514	6,201	222,536	57,365
Disposables, Service and Accessories [Member]
Revenue:
Total revenue	5,086,156	6,546,115	10,595,867	13,256,873
Cost of revenue:
Total cost of revenue	$ 680,937	$ 894,760	$ 1,320,800	$ 2,009,119