INCOME TAXES - TEMPORARY DIFFERENCES TO THE COMPONENTS OF DEFERRED TAX ASSETS (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Inventory	$ 2,993	$ 2,005
Accrued compensation	295	122
Stock and Stock Options	2,322	1,858
Research and development tax credit	1,308	990
Research and development expense	2,571	1,417
Deferred revenue	1,441	2,052
Property and equipment	298	3,469
Net operating loss carryforwards – domestic	8,757	11,676
Foreign tax credit carryforward	64	64
Sales-type leases	1,324
Sales-type leases		1,968
Convertible debt equity component	(8,691)	(9,421)
Foreign intangible	(11,311)	(691)
Other	(1,124)	(179)
Deferred tax assets, gross	247	11,394
Valuation allowance	6,409	5,656
Total net deferred tax assets (liabilities)	$ (6,162)
Total net deferred tax assets (liabilities)		$ 5,738