Condensed Consolidated Statements Of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021
Cash flows from operating activities:
Net loss	$ (31,269)	$ (33,962)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation	347	229
Amortization of intangible assets	333	333
Stock-based compensation	3,720	9,413
Net premium amortization and discount on available-for-sale securities		13
Changes in operating assets and liabilities:
Accounts receivable	53
Inventory	(2,047)	(2,691)
Prepaid expenses and other current assets	1,112	(2,454)
Other receivables	(30)	23
Right-of-use assets	352	319
Accounts payable	(931)	1,041
Accrued expenses	296	(754)
Deferred revenue	16
Lease liabilities	(369)	(192)
Accrued interest on note payable	1	629
Net cash used in operating activities	(28,416)	(28,053)
Cash flows from investing activities:
Purchases of property and equipment	(298)	(146)
Maturities of investments		8,000
Net cash provided by (used in) investing activities	(298)	7,854
Cash flows from financing activities:
Proceeds from issuance of common stock under employee stock purchase plan	372	421
Proceeds from exercises of warrants		4,217
Proceeds from exercises of stock options		678
Proceeds from issuance of common stock	14,963	48,348
Proceeds from issuance of related party note		1,730
Tax payments related to shares withheld for vested restricted stock units		(232)
Payments made on insurance loan agreement	(437)
Net cash provided by financing activities	14,898	55,162
Net increase (decrease) in cash and cash equivalents	(13,816)	34,963
Cash and cash equivalents at beginning of period	28,614	12,463
Cash and cash equivalents at end of period	14,798	47,426
Supplemental disclosure of noncash investing and financing activities:
Equipment purchases included in accounts payable and accrued expenses	(27)	65
Change in unrealized gains on available-for-sale securities		1
Accrued interest settled via issuance of common stock from private placement equity offering		629
Related party other receivable from issuance of common stock from private placement equity offering		8,371
Other receivable from issuance of common stock	13	$ 25
Issuance costs for rights offering in accounts payable and accrued expenses	$ (74)