Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2019

Accounting Policies [Abstract]

Summary of Estimated Lives of Assets

Depreciation is recorded using the straight-line method over the estimated useful lives of the assets as follows:

Machinery, manufacturing and demonstration equipment	3-5 years
Computer equipment	3 years
Furniture	5 years
Leasehold improvements	Lesser of lease term or 3 to 10 years

Summary of Revenue Disaggregated by Type and Geography

The following table presents revenue disaggregated by type and geography:

	Year Ended December 31,
	2019		2018
	(in thousands)
U.S.
Systems	$	90	$	2,556
Instruments and accessories	108		967
Services	338		255
Total U.S. revenue	536		3,778
Outside of U.S. ("OUS")
Systems	5,459		16,193
Instruments and accessories	1,447		3,552
Services	1,089		579
Total OUS revenue	7,995		20,324
Total
Systems	5,549		18,749
Instruments and accessories	1,555		4,519
Services	1,427		834
Total revenue	$	8,531	$	24,102

Lessee, Operating Lease, Liability, Maturity

The following table presents the minimum lease payments as of December 31, 2018 (in thousands):

January 1, 2019 to December 31, 2019	$	929
January 1, 2020 to December 31, 2020	399
January 1, 2021 to December 31, 2021	385
January 1, 2022 to December 31, 2022	175
January 1, 2023 to December 31, 2023	38
Thereafter	—
Total minimum lease payments	$	1,926

The following table presents the minimum lease payments as of December 31, 2019 (in thousands):

January 1, 2020 to December 31, 2020	$	1,372
January 1, 2021 to December 31, 2021	716
January 1, 2022 to December 31, 2022	454
January 1, 2023 to December 31, 2023	207
January 1, 2024 to December 31, 2024	28
Thereafter	—
Total minimum lease payments	$	2,778
Less: Amount of lease payments representing interest	(266		)
Present value of future minimum lease payments	$	2,512