Other accrued expenses (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Other accrued expenses
Inventory purchases	$ 558	$ 568
Property and equipment purchases	202	229
Royalties	1,096	1,250
Professional services	1,861	2,126
Leasehold improvements	1,081
Development costs	977	566
Tax liabilities	806	430
Other	1,443	1,317
Total accrued expenses	$ 8,024	$ 6,486