Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Current Assets:
Cash and cash equivalents	$ 23,014	$ 37,323
Short-term investments	20,073
Trade accounts receivable, net of allowance for doubtful accounts of $109 and $61, respectively	3,884	3,619
Inventory, net	469	550
Prepaid expenses and other current assets	1,468	4,044
Total current assets	48,908	45,536
Assets for lease, net	2,478	1,643
Property and equipment, net	667	394
Long-term investments	821	821
Long-term notes receivable	4,679
Other non-current assets	2,842	332
Long-term deferred tax assets	2,298	1,946
Total assets	62,693	50,672
Current liabilities:
Accounts payable	835	443
Accrued expenses	4,748	3,436
Deferred revenue	1,160	921
Other short-term liabilities	114	80
Total current liabilities	6,857	4,880
Long-term liabilities:
Other long-term liabilities	160	245
Total long-term liabilities	160	245
Commitments and contingencies (Note 13)
Stockholders' equity:
Common stock, $0.001 par value; 50,000,000 shares authorized; 6,906,544, and 6,824,380 shares issued, and 6,692,122, and 6,758,458 shares outstanding (treasury shares of 214,422 and 65,922), respectively	7	7
Additional paid-in capital	16,449	20,645
Retained earnings	39,220	24,895
Total stockholders' equity	55,676	45,547
Total liabilities and stockholders' equity	$ 62,693	$ 50,672