Supplemental Balance Sheet Information (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Inventory:
Raw materials	$ 1,007	$ 1,020
Sub-assemblies	1,271	1,379
Finished goods	1,189	1,342
Total inventory	3,467	3,741
Prepaid expenses and other current assets:
Prepaid insurance	191	110
Professional services	65
Patents	10	13
Prepaid advertising and marketing	21	41
Taxes	26	47
Other current assets	70	126
Total prepaid expenses and other current assets	383	337
Accrued and other liabilities:
Payroll and benefits	602	701
Accrued legal settlements	200	200
Customer deposits	643	639
Taxes	52	61
Accrued professional	377	155
Other liabilities	56	58
Total accrued and other liabilities	$ 1,930	$ 1,814