Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Current assets:
Cash and cash equivalents	$ 17,578	$ 23,328
Short-term investments	12,136	2,981
Accounts receivable, less current expected credit loss of $111 and $110, respectively	6,729	7,729
Inventories, net	439	392
Prepaid expenses and other current assets	1,439	1,395
Total current assets	38,321	35,825
Property and equipment, net	4,539	4,435
Goodwill	2,116	2,116
Other intangible assets, net	358	397
Right-of-use operating lease assets	609	197
Long-term investments	3,664	6,360
Other assets	781	794
Total assets	50,388	50,124
Current liabilities:
Accounts payable	2,421	2,710
Accrued liabilities:
Operating lease liabilities - current	81	125
Employee compensation	1,252	1,105
Other accrued liabilities	1,934	826
Total current liabilities	5,688	4,766
Operating lease liabilities - non-current	533	66
Deferred income taxes	172	177
Other liabilities	281	274
Total liabilities	6,674	5,283
Commitments and contingencies (Note 9)
Stockholders’ equity:
Common stock, $.01 par value, 40,000,000 shares authorized, 31,361,303 and 31,272,303 shares issued, and 30,385,297 and 30,296,297 shares outstanding in 2023 and 2022, respectively	313	313
Additional paid-in capital	164,853	164,422
Accumulated deficit	(117,529)	(115,991)
Accumulated other comprehensive loss	(1,748)	(1,728)
Nil coupon perpetual loan notes	76	76
Treasury stock, at cost (Note 5)	(2,251)	(2,251)
Total stockholders’ equity	43,714	44,841
Total liabilities and stockholders’ equity	$ 50,388	$ 50,124