Consolidated Statements of Operations and Comprehensive Loss - USD ($) shares in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Sales:
Total sales, net	$ 6,599,000	$ 12,508,000	$ 18,230,000
Product cost of goods sold	1,738,000	1,503,000	2,784,000
Gross profit	4,861,000	11,005,000	15,446,000
Research and development	184,000	259,000	410,000
Sales and marketing	8,767,000	12,789,000	13,711,000
General and administrative	5,310,000	5,828,000	8,636,000
Total operating expenses	14,261,000	18,876,000	22,757,000
Operating loss	(9,400,000)	(7,871,000)	(7,311,000)
Non-cash gain (loss) on changes in fair value of warrant liability	749,000	1,311,000	(101,000)
Non-cash gain on changes in fair value of embedded derivative liability	424,000
Other (expense) income, net	1,425,000	(19,000)	(12,000)
Loss before provision for income taxes	(9,652,000)	(6,541,000)	(7,400,000)
Provision for income taxes	(6,000)	(4,000)	(3,000)
Net loss and comprehensive loss	(9,658,000)	(6,545,000)	(7,403,000)
Less: Preferred deemed dividend	800,000
Less: Retained earnings reduction related to warrants down round feature triggered	29,000
Net loss attributable to common stockholders	$ (10,487,000)	$ (6,545,000)	$ (7,403,000)
Net loss per share attributable to common stockholders (basic) (in dollars per share)	$ (0.48)	$ (0.39)	$ (0.48)
Net loss per share attributable to common stockholders (diluted) (in dollars per share)	$ (0.48)	$ (0.46)	$ (0.48)
Weighted-average shares of common stock outstanding used in computing net loss per share of common stock (basic) (in shares)	21,641	16,921	15,324
Weighted-average shares of common stock outstanding used in computing net loss per share of common stock (diluted) (in shares)	21,641	17,058	15,324
Product [Member]
Sales:
Total sales, net	$ 6,556,000	$ 12,474,000	$ 18,127,000
Product and Service, Other [Member]
Sales:
Total sales, net	$ 43,000	$ 34,000	$ 103,000