Composition of Certain Consolidated Financial Statement Items - Other Current Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Accrued purchases	$ 134	$ 432
Interest	390	403
Professional services	579	339
Sales tax	482	302
Clinical trial expenses	117	47
Other	1,132	454
Total other current liabilities	$ 2,834	$ 1,977

Accrued Clinical Trial Expenses

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- Definition

Accrued Purchases

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- Definition

Carrying value as of the balance sheet date of obligations incurred through that date and payable for professional fees, such as for legal and accounting services received. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

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Carrying value as of the balance sheet date of [accrued] interest payable on all forms of debt, including trade payables, that has been incurred and is unpaid. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

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Amount of expenses incurred but not yet paid classified as other, due within one year or the normal operating cycle, if longer.

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Amount of liabilities classified as other, due within one year or the normal operating cycle, if longer.

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Carrying value as of the balance sheet date of liabilities incurred through that date and payable for statutory sales and use taxes, including value added tax. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

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