CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands	3 Months Ended
	Apr. 02, 2021	Apr. 03, 2020
Income Statement [Abstract]
Net sales	$ 50,752,000	$ 35,187,000
Cost of sales	11,610,000	10,427,000
Gross profit	39,142,000	24,760,000
Selling, general and administrative expenses:
General and administrative	10,212,000	7,969,000
Selling and marketing	13,201,000	11,028,000
Research and development	8,259,000	6,898,000
Total selling, general and administrative expenses	31,672,000	25,895,000
Operating income (loss)	7,470,000	(1,135,000)
Other expense, net:
Interest income (expense), net	(7,000)	216,000
Loss on foreign currency transactions	(1,299,000)	(468,000)
Royalty income	160,000	94,000
Other income (expense), net	(85,000)	1,000
Total other expense, net	(1,231,000)	(157,000)
Income (loss) before income taxes	6,239,000	(1,292,000)
Provision (benefit) for income taxes	1,247,000	(1,158,000)
Net income (loss)	$ 4,992,000	$ (134,000)
Net income (loss) per share:
Basic	$ 0.11	$ 0.00
Diluted	$ 0.10	$ 0.00
Weighted average shares outstanding:
Basic	46,617	44,953
Diluted	49,213	44,953