Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2021

Accounting Policies [Abstract]

Schedule of revenue information by major geographic area

Revenue by geographic areas is based on the location of the customer. The following is a summary of revenue information by major geographic area:

	Years Ended December 31,
(in thousands)	2021		2020		2019
Domestic	$	43,264	$	24,964	$	16,987
Germany		6,618		12,157		6,696
Belgium		5,119		4,916		4,152
Switzerland		2,605		4,423		4,000
All other countries		1,143		873		509
Total revenues	$	58,749	$	47,333	$	32,344

Schedule of reconciliation of cash and cash equivalents and restricted cash in financial statements

The following table provides a reconciliation of cash and cash equivalents and restricted cash.

	December 31,
(in thousands)	2021		2020		2019
Cash and cash equivalents	$	286,487	$	377,581	$	6,261
Restricted cash		481		2,316		3,017
Total cash and cash equivalents and restricted cash	$	286,968	$	379,897	$	9,278

Schedule of changes in R&D contract asset and contract liability balance

The following table shows the significant changes in the R&D contract asset and contract liability balances.

	December 31, 2021					December 31, 2020
(in thousands)	Contract Assets		Contract Liabilities			Contract Liabilities
Beginning balance	$	-	$	(2,115	)	$	(4,240	)
Revenue recognized		2,128		4,157			4,712
Unearned consideration received		-		(2,256	)		(2,587	)
Ending balance	$	2,128	$	(214	)	$	(2,115	)

Schedule of Stock-based compensation expense

The following table sets forth the allocation of our stock-based compensation expense.

	Years Ended December 31,
(in thousands)	2021		2020		2019
Cost of revenue	$	109	$	126	$	76
Selling, general and administrative		48,782		3,313		5,036
Research and development		7,017		206		159
Total stock-based compensation	$	55,908	$	3,645	$	5,271