Condensed Statements of Operations - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Revenue:
Total revenue	$ 4,706,378	$ 3,723,484	$ 13,775,796	$ 6,855,409
Cost of revenue	1,239,702	1,088,987	3,827,447	3,621,193
Gross margin	3,466,676	2,634,497	9,948,349	3,234,216
Operating expenses:
Selling, general and administrative	4,709,885	4,258,347	15,132,468	12,910,251
Research and development	3,561,459	3,478,419	8,909,729	6,364,371
Total operating expenses	8,271,344	7,736,766	24,042,197	19,274,622
Operating loss	(4,804,668)	(5,102,269)	(14,093,848)	(16,040,406)
Other income (expense):
Interest expense	(234,392)	(300,272)	(650,215)	(1,048,750)
Interest income	195,652	22,438	526,588	52,157
Loss on extinguishment of Growth Term Loan			(105,064)
Total other income (expense)	(38,740)	(277,834)	(228,691)	(996,593)
Net loss before income taxes	(4,843,408)	(5,380,103)	(14,322,539)	(17,036,999)
Provision for income taxes		743	3,545	1,023
Net loss	$ (4,843,408)	$ (5,380,846)	$ (14,326,084)	$ (17,038,022)
Net loss per share, basic and diluted	$ (0.17)	$ (0.46)	$ (0.53)	$ (1.74)
Shares used in computing net loss per share, basic and diluted	28,434,406	11,603,617	27,184,968	9,794,651
Product and Product-related Services
Revenue:
Total revenue	$ 1,314,844	$ 1,592,790	$ 5,071,702	$ 4,422,304
Collaborative Development Services
Revenue:
Total revenue	$ 3,391,534	$ 2,130,694	$ 8,704,094	$ 2,433,105