Balance Sheets - USD ($)	Dec. 31, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 10,943,000	$ 16,410,000
Accounts receivable, net of allowance for doubtful accounts of $19 and $260 at December 31, 2019 and 2018, respectively	1,458,000	1,154,000
Inventories	3,912,000	3,422,000
Prepaid expenses and other current assets	311,000	635,000
Total current assets	16,624,000	21,621,000
Right of use asset	4,856,000
Property and equipment, net	1,661,000	2,078,000
Other assets	684,000
Total assets	23,825,000	23,699,000
Current liabilities:
Accounts payable	663,000	1,148,000
Accrued compensation	1,782,000	1,197,000
Series A preferred stock dividends payable		2,918,000
Accrued expenses and other current liabilities	654,000	1,449,000
Leasehold liability, current portion	722,000
Borrowings	8,967,000	7,486,000
Total current liabilities	12,788,000	14,198,000
Leasehold liability, long-term portion	4,135,000
Other long-term liabilities	7,000	41,000
Total liabilities	16,930,000	14,239,000
Commitments and contingencies (Note 8)
Stockholders’ equity:
Convertible preferred stock issuable in series, par value of $0.001 Shares authorized: 5,000,000 at December 31, 2019 and 2018 Shares issued and outstanding: 48,503 and 45,671 at December 31, 2019 and 2018, respectively; aggregate liquidation preference related to Series A convertible preferred stock of $48,325 and $44,718 at December 31, 2019 and 2018, respectively
Common stock, par value of $0.001 Shares authorized: 100,000,000 at December 31, 2019 and 2018 Shares issued and outstanding: 10,364,663 and 3,492,200 at December 31, 2019 and 2018, respectively	10,000	3,000
Additional paid-in capital	355,220,000	338,342,000
Accumulated deficit	(348,335,000)	(328,885,000)
Total stockholders’ equity	6,895,000	9,460,000
Total liabilities and stockholders’ equity	$ 23,825,000	$ 23,699,000