Accrued Expense (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Accrued Expense
Accrued expense	$ 909	$ 770
Accrued vacation and bonus expenses	400	400
Manufacturing and testing services	200
Professional and consulting fees	100
Accrued legal and patent fees	100	100
Accrued franchise tax expense		100
Other accrued expenses	$ 100	100
Manufacturing expenses		$ 100