Condensed Consolidated Balance Sheets - USD ($)	Jun. 30, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 10,935,000	$ 11,703,000
Accounts receivable	819,000	924,000
Prepaid expenses and other current assets	870,000	758,000
Inventories	66,000	25,000
Total current assets	12,690,000	13,410,000
Property and equipment, net	360,000	353,000
Other assets	41,000	65,000
Total assets	13,091,000	13,828,000
Current liabilities:
Accounts payable	1,122,000	1,158,000
Accrued liabilities	2,459,000	2,588,000
Short-term debt	587,000	193,000
Other current liabilities	31,000	39,000
Total current liabilities	4,199,000	3,978,000
Non-current liabilities:
Long-term debt	1,615,000	1,099,000
Other non-current liabilities	10,000	13,000
Total liabilities	5,824,000	5,090,000
Commitments and contingencies (Note 3)
Stockholders' equity:
Common stock, par value $0.001 per share, 150,000,000 shares authorized at June 30, 2020 and December 31, 2019; 100,525,090 and 97,286,157 shares issued and outstanding atJune 30, 2020 and December 31, 2019, respectively	101,000	97,000
Additional paid-in capital	436,864,000	430,802,000
Accumulated deficit	(429,698,000)	(422,161,000)
Total stockholders' equity	7,267,000	8,738,000
Total liabilities and stockholders' equity	$ 13,091,000	$ 13,828,000