Condensed Consolidated Balance Sheets (Current Period Unaudited) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Current assets:
Cash and cash equivalents	$ 15,698	$ 23,328
Short-term investments	11,067	2,981
Accounts receivable, net	6,755	7,729
Inventories, net	509	392
Prepaid expenses and other current assets	1,350	1,395
Total current assets	35,379	35,825
Property and equipment, net of accumulated depreciation of $18,646 and $18,557, respectively	4,370	4,435
Goodwill	2,116	2,116
Other intangible assets, net of accumulated amortization of $418 and $406, respectively	401	397
Right-of-use operating lease assets, net	166	197
Long-term investments	7,054	6,360
Other assets	796	794
Total assets	50,282	50,124
Current liabilities:
Accounts payable	3,651	2,710
Accrued liabilities:
Operating lease liabilities - current	109	125
Employee compensation	588	1,105
Other accrued liabilities	827	826
Total current liabilities	5,175	4,766
Operating lease liabilities - non-current	51	66
Deferred income taxes, net	177	177
Other liabilities	277	274
Total liabilities	5,680	5,283
Stockholders’ equity:
Common stock, $.01 par value, 40,000,000 shares authorized, 31,272,303 and 31,272,303 shares issued, and 30,296,297 and 30,296,297 shares outstanding, respectively	313	313
Additional paid-in capital	164,511	164,422
Accumulated deficit	(116,405)	(115,991)
Accumulated other comprehensive loss	(1,642)	(1,728)
Nil coupon perpetual loan notes	76	76
Treasury stock, at cost	(2,251)	(2,251)
Total stockholders’ equity	44,602	44,841
Total liabilities and stockholders’ equity	$ 50,282	$ 50,124