Condensed Consolidated Balance Sheets (Current Period Unaudited) - USD ($) $ in Thousands	Mar. 31, 2025	Dec. 31, 2024
Current assets:
Cash and cash equivalents	$ 11,821	$ 8,510
Short-term investments	9,968	10,184
Accounts receivable, less current expected credit loss of $106 and $106, respectively	5,635	9,368
Inventories, net	534	397
Prepaid expenses and other current assets	1,188	1,160
Total current assets	29,146	29,619
Property and equipment, net of accumulated depreciation of $18,947 and $18,958, respectively	4,979	5,084
Goodwill	2,116	2,116
Other intangible assets, net of accumulated amortization of $534 and $525, respectively	324	327
Right-of-use operating lease assets, net	566	585
Long-term investments	9,381	10,875
Other assets	197	191
Total assets	46,709	48,797
Current liabilities:
Accounts payable	1,587	2,915
Accrued liabilities:
Operating lease liabilities - current	75	77
Employee compensation	1,286	1,248
Other accrued liabilities	1,339	1,615
Total current liabilities	4,287	5,855
Operating lease liabilities - non-current	532	548
Deferred income taxes, net	176	176
Other liabilities	276	263
Total liabilities	5,271	6,842
Stockholders’ equity:
Common stock, $.01 par value, 40,000,000 shares authorized, 31,852,657 and 31,767,329 shares issued, and 30,769,258 and 30,708,273 shares outstanding, respectively	318	317
Additional paid-in capital	165,405	165,295
Accumulated deficit	(120,211)	(119,472)
Accumulated other comprehensive loss	(1,780)	(1,915)
Nil coupon perpetual loan notes	76	76
Treasury stock, at cost	(2,370)	(2,346)
Total stockholders’ equity	41,438	41,955
Total liabilities and stockholders’ equity	$ 46,709	$ 48,797