REVENUE - Summary of Revenue Disaggregated by Types and Geography (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Disaggregation Of Revenue [Line Items]
Total revenue	$ 19,177	$ 10,086	$ 49,732	$ 38,560
Product
Disaggregation Of Revenue [Line Items]
Total revenue	14,126	6,210	36,422	28,295
Service
Disaggregation Of Revenue [Line Items]
Total revenue	4,933	3,758	12,954	9,909
Distribution rights
Disaggregation Of Revenue [Line Items]
Total revenue	118	118	356	356
U.S.
Disaggregation Of Revenue [Line Items]
Total revenue	8,892	2,786	28,801	13,584
U.S. | Product
Disaggregation Of Revenue [Line Items]
Total revenue	6,097	618	21,304	7,920
U.S. | Service
Disaggregation Of Revenue [Line Items]
Total revenue	2,795	2,168	7,497	5,664
Outside of U.S. ("OUS")
Disaggregation Of Revenue [Line Items]
Total revenue	10,285	7,300	20,931	24,976
Outside of U.S. ("OUS") | Product
Disaggregation Of Revenue [Line Items]
Total revenue	8,029	5,592	15,118	20,375
Outside of U.S. ("OUS") | Service
Disaggregation Of Revenue [Line Items]
Total revenue	2,138	1,590	5,457	4,245
Outside of U.S. ("OUS") | Distribution rights
Disaggregation Of Revenue [Line Items]
Total revenue	$ 118	$ 118	$ 356	$ 356