Condensed Consolidated Balance Sheets (Current Period Unaudited) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Current assets:
Cash and cash equivalents	$ 10,404	$ 17,578
Short-term investments	9,669	12,136
Accounts receivable, less current expected credit loss of $106 and $111, respectively	8,651	6,729
Inventories, net	462	439
Prepaid expenses and other current assets	1,117	1,439
Total current assets	30,303	38,321
Property and equipment, net of accumulated depreciation of $18,823 and $18,703, respectively	4,571	4,539
Goodwill	2,116	2,116
Other intangible assets, net of accumulated amortization of $499 and $468, respectively	337	358
Right-of-use operating lease assets, net	551	609
Long-term investments	10,360	3,664
Other assets	756	781
Total assets	48,994	50,388
Current liabilities:
Accounts payable	2,938	2,421
Accrued liabilities:
Operating lease liabilities - current	94	81
Employee compensation	731	1,252
Other accrued liabilities	719	1,934
Total current liabilities	4,482	5,688
Operating lease liabilities - non-current	495	533
Deferred income taxes, net	172	172
Other liabilities	276	281
Total liabilities	5,425	6,674
Stockholders’ equity:
Common stock, $.01 par value, 40,000,000 shares authorized, 31,767,329 and 31,361,303 shares issued, and 30,708,273 and 30,385,297 shares outstanding, respectively	317	313
Additional paid-in capital	165,077	164,853
Accumulated deficit	(117,669)	(117,529)
Accumulated other comprehensive loss	(1,886)	(1,748)
Nil coupon perpetual loan notes	76	76
Treasury stock, at cost	(2,346)	(2,251)
Total stockholders’ equity	43,569	43,714
Total liabilities and stockholders’ equity	$ 48,994	$ 50,388