Statements of Cash Flows - USD ($)	6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021
Cash flows from operating activities:
Net loss	$ (23,988,000)	$ (34,765,000)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation	1,057,000	1,029,000
Amortization	124,000	67,000
Noncash stock-based compensation	1,433,000	1,585,000
Noncash interest	797,000	864,000
Changes in operating assets and liabilities:
Accounts receivable	(554,000)	(302,000)
Inventory	(1,374,000)	(3,462,000)
Prepaid expenses and other assets	1,267,000	552,000
Accounts payable and accrued expenses	3,643,000	4,494,000
Lease liability	(90,000)	(66,000)
Net cash used in operating activities	(17,685,000)	(30,004,000)
Cash flows from investing activities:
Sales and maturities of marketable securities		34,729,000
Acquisition of property and equipment	(133,000)	(149,000)
Net cash (used in) provided by investing activities	(133,000)	34,580,000
Cash flows from financing activities:
Repayments of long-term debt	(5,000,000)
Proceeds from exercise of stock options		75,000
Net cash provided by financing activities	11,702,000	7,079,000
Net (decrease) increase in cash and cash equivalents	(6,116,000)	11,655,000
Cash and cash equivalents, beginning of period	19,143,000	14,463,000
Cash and cash equivalents, end of period	13,027,000	26,118,000
Supplemental disclosure of noncash financing activities
Warrants issued in connection with long-term debt		1,080,000
Warrants issued in connection with preferred stock offering	2,101,000
Supplemental cash flow information
Interest paid	898,000	1,182,000
Series A Convertible Preferred Stock
Supplemental disclosure of noncash financing activities
Conversion of Series preferred stock into common stock	897,000
Series B Convertible Preferred Stock
Supplemental disclosure of noncash financing activities
Conversion of Series preferred stock into common stock	887,000
Public offering
Cash flows from financing activities:
Proceeds from issuance of preferred stock in registered direct offering, net of offering costs	4,129,000
At-the-market sales
Cash flows from financing activities:
Proceeds from At-the-Market sales of common stock, net of offering costs	$ 12,573,000	$ 7,004,000