Revenue - Net Revenue Disaggregated into Categories (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Disaggregation Of Revenue [Line Items]
Total Revenue	$ 19,115	$ 12,299
US
Disaggregation Of Revenue [Line Items]
Total Revenue	14,341	10,049
International
Disaggregation Of Revenue [Line Items]
Total Revenue	4,774	2,250
Product Revenue, Capital Equipment
Disaggregation Of Revenue [Line Items]
Total Revenue	4,998	2,015
Product Revenue, Capital Equipment | US
Disaggregation Of Revenue [Line Items]
Total Revenue	3,301	1,510
Product Revenue, Capital Equipment | International
Disaggregation Of Revenue [Line Items]
Total Revenue	1,697	505
Product Revenue, Disposable
Disaggregation Of Revenue [Line Items]
Total Revenue	12,430	9,019
Product Revenue, Disposable | US
Disaggregation Of Revenue [Line Items]
Total Revenue	9,694	7,547
Product Revenue, Disposable | International
Disaggregation Of Revenue [Line Items]
Total Revenue	2,736	1,472
Subtotal Product Revenue
Disaggregation Of Revenue [Line Items]
Total Revenue	17,428	11,034
Subtotal Product Revenue | US
Disaggregation Of Revenue [Line Items]
Total Revenue	12,995	9,057
Subtotal Product Revenue | International
Disaggregation Of Revenue [Line Items]
Total Revenue	4,433	1,977
Lease Revenue, Capital Equipment
Disaggregation Of Revenue [Line Items]
Total Revenue	644
Lease Revenue, Capital Equipment | US
Disaggregation Of Revenue [Line Items]
Total Revenue	627
Lease Revenue, Capital Equipment | International
Disaggregation Of Revenue [Line Items]
Total Revenue	17
Lease Revenue, Other
Disaggregation Of Revenue [Line Items]
Total Revenue	392
Lease Revenue, Other | US
Disaggregation Of Revenue [Line Items]
Total Revenue	317
Lease Revenue, Other | International
Disaggregation Of Revenue [Line Items]
Total Revenue	75
Service and Other Revenue
Disaggregation Of Revenue [Line Items]
Total Revenue	651	602
Service and Other Revenue | US
Disaggregation Of Revenue [Line Items]
Total Revenue	402	329
Service and Other Revenue | International
Disaggregation Of Revenue [Line Items]
Total Revenue	$ 249	273
Lease Revenue
Disaggregation Of Revenue [Line Items]
Total Revenue		663
Lease Revenue | US
Disaggregation Of Revenue [Line Items]
Total Revenue		$ 663