CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) - USD ($)	Mar. 31, 2019	Dec. 31, 2018
Current Assets
Cash and cash equivalents	$ 6,251,884	$ 12,484,256
Accounts receivable, net	16,881,672	13,145,934
Inventories	1,551,419	1,628,817
Investment in debt securities	4,699,954	2,892,190
Prepaid and other current assets	2,252,755	1,750,994
Total Current Assets	31,637,684	31,902,191
Property and Equipment, Net	899,792	891,029
Patent Rights, Net	409,640	433,737
Deposits	24,272	24,272
Operating Lease Right-of-Use Assets, Net	749,114	0
Total Assets	33,720,502	33,251,229
Current Liabilities
Accounts payable and accrued expenses	4,075,214	5,166,239
Deferred revenue, current portion	744,996	722,025
Operating lease liabilities, current portion	240,972
Product warranties	137,942	136,217
Total Current Liabilities	5,199,124	6,024,481
Operating Lease Liabilities	510,784
Deferred Revenue, Net of Current Portion	815,164	766,732
Total Liabilities	6,525,072	6,791,213
Stockholders' Equity
Preferred stock, 5,000,000 shares authorized and none issued and outstanding
Common stock, $0.01 par value - 50,000,000 authorized; 16,546,196 issued and 16,512,742 outstanding at March 31, 2019; 16,145,915 issued and 16,112,461 outstanding at December 31, 2018	165,461	161,459
Additional paid-in capital	42,810,335	39,957,905
Treasury stock, 33,454 shares at cost, at March 31, 2019 and December 31, 2018, respectively	(133,816)	(133,816)
Accumulated deficit	(15,646,550)	(13,525,532)
Total Stockholders' Equity	27,195,430	26,460,016
Total Liabilities and Stockholders' Equity	$ 33,720,502	$ 33,251,229